diff --git a/src/functionalTest/kotlin/kotlinx/validation/test/IgnoredProjectsTests.kt b/src/functionalTest/kotlin/kotlinx/validation/test/IgnoredProjectsTests.kt
new file mode 100644
index 00000000..c2672b8f
--- /dev/null
+++ b/src/functionalTest/kotlin/kotlinx/validation/test/IgnoredProjectsTests.kt
@@ -0,0 +1,133 @@
+/*
+ * Copyright 2016-2020 JetBrains s.r.o.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.validation.test
+
+import kotlinx.validation.api.*
+import kotlinx.validation.api.assertTaskSuccess
+import kotlinx.validation.api.buildGradleKts
+import kotlinx.validation.api.resolve
+import kotlinx.validation.api.runner
+import kotlinx.validation.api.test
+import org.junit.Test
+
+internal class IgnoredProjectsTests : BaseKotlinGradleTest() {
+    /**
+     * Creates a single project with 2 (Kotlin and Java Android Library) modules, applies
+     * the plugin on the root project.
+     */
+
+    @Test
+    fun `apiCheck should succeed when a project does not have an api file but is ignored via ignoredProjects`() {
+        val runner = test {
+            createProjectHierarchyWithPluginOnRoot()
+
+            // Ignore "sub1" project
+            buildGradleKts {
+                resolve("examples/gradle/configuration/ignoredProjects/ignoreSub1.gradle.kts")
+            }
+
+            emptyApiFile(projectName = rootProjectDir.name)
+
+            dir("sub1") {
+                dir("subsub1") {
+                    emptyApiFile(projectName = "subsub1")
+                }
+                dir("subsub2") {
+                    emptyApiFile(projectName = "subsub2")
+                }
+            }
+
+            dir("sub2") {
+                emptyApiFile(projectName = "sub2")
+            }
+
+            runner {
+                arguments.add("check")
+            }
+        }
+
+        runner.build().apply {
+            assertTaskSuccess(":apiCheck")
+            assertTaskSuccess(":sub1:subsub1:apiCheck")
+            assertTaskSuccess(":sub1:subsub2:apiCheck")
+            assertTaskSuccess(":sub2:apiCheck")
+        }
+    }
+
+    @Test
+    fun `apiCheck should succeed ignoring a project and its subprojects`() {
+        val runner = test {
+            createProjectHierarchyWithPluginOnRoot()
+
+            // Ignore "sub1" project and its subprojects ("subsub1" and "subsub2")
+            buildGradleKts {
+                resolve("examples/gradle/configuration/ignoredProjects/ignoreSub1.gradle.kts")
+                resolve("examples/gradle/configuration/ignoredProjects/ignoreSubProjects.gradle.kts")
+            }
+
+            emptyApiFile(projectName = rootProjectDir.name)
+
+            dir("sub1") {
+                dir("subsub1") {}
+                dir("subsub2") {}
+            }
+
+            dir("sub2") {
+                emptyApiFile(projectName = "sub2")
+            }
+
+            runner {
+                arguments.add("check")
+            }
+        }
+
+        runner.build().apply {
+            assertTaskSuccess(":apiCheck")
+            assertTaskSuccess(":sub2:apiCheck")
+        }
+    }
+
+    /**
+     * Sets up a project hierarchy like this:
+     * ```
+     * build.gradle.kts (with the plugin)
+     * settings.gradle.kts (including refs to 4 subprojects)
+     * sub1/
+     *    build.gradle.kts
+     *    subsub1/build.gradle.kts
+     *    subsub2/build.gradle.kts
+     * sub2/build.gradle.kts
+     * ```
+     */
+    private fun BaseKotlinScope.createProjectHierarchyWithPluginOnRoot() {
+        settingsGradleKts {
+            resolve("examples/gradle/settings/settings-with-hierarchy.gradle.kts")
+        }
+        buildGradleKts {
+            resolve("examples/gradle/base/withPlugin.gradle.kts")
+        }
+        dir("sub1") {
+            buildGradleKts {
+                resolve("examples/gradle/base/withoutPlugin-noKotlinVersion.gradle.kts")
+            }
+            dir("subsub1") {
+                buildGradleKts {
+                    resolve("examples/gradle/base/withoutPlugin-noKotlinVersion.gradle.kts")
+                }
+            }
+            dir("subsub2") {
+                buildGradleKts {
+                    resolve("examples/gradle/base/withoutPlugin-noKotlinVersion.gradle.kts")
+                }
+            }
+        }
+        dir("sub2") {
+            buildGradleKts {
+                resolve("examples/gradle/base/withoutPlugin-noKotlinVersion.gradle.kts")
+            }
+        }
+    }
+}
diff --git a/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSub1.gradle.kts b/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSub1.gradle.kts
new file mode 100644
index 00000000..acc2956f
--- /dev/null
+++ b/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSub1.gradle.kts
@@ -0,0 +1,3 @@
+configure<kotlinx.validation.ApiValidationExtension> {
+    ignoredProjects.add("sub1")
+}
diff --git a/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSubprojects.gradle.kts b/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSubprojects.gradle.kts
new file mode 100644
index 00000000..8614ee93
--- /dev/null
+++ b/src/functionalTest/resources/examples/gradle/configuration/ignoredProjects/ignoreSubprojects.gradle.kts
@@ -0,0 +1,3 @@
+configure<kotlinx.validation.ApiValidationExtension> {
+    ignoreSubprojects = true
+}
diff --git a/src/main/kotlin/ApiValidationExtension.kt b/src/main/kotlin/ApiValidationExtension.kt
index deb85435..c9abecc8 100644
--- a/src/main/kotlin/ApiValidationExtension.kt
+++ b/src/main/kotlin/ApiValidationExtension.kt
@@ -23,6 +23,11 @@ open class ApiValidationExtension {
      */
     public var ignoredProjects: MutableSet<String> = HashSet()
 
+    /**
+     * Should projects specified in [ignoredProjects] also have their subprojects ignored
+     */
+    public var ignoreSubprojects: Boolean = false
+
     /**
      * Fully qualified names of annotations that effectively exclude declarations from being public.
      * Example of such annotation could be `kotlinx.coroutines.InternalCoroutinesApi`.
diff --git a/src/main/kotlin/BinaryCompatibilityValidatorPlugin.kt b/src/main/kotlin/BinaryCompatibilityValidatorPlugin.kt
index c0217ae4..03db00ca 100644
--- a/src/main/kotlin/BinaryCompatibilityValidatorPlugin.kt
+++ b/src/main/kotlin/BinaryCompatibilityValidatorPlugin.kt
@@ -27,6 +27,17 @@ class BinaryCompatibilityValidatorPlugin : Plugin<Project> {
 
     private fun Project.validateExtension(extension: ApiValidationExtension) {
         afterEvaluate {
+            val ignoredSubprojects = extension.ignoredProjects
+                .flatMap { projectName ->
+                    allprojects
+                    .filter { project -> project.name == projectName }
+                    .flatMap { project -> project.subprojects.map { it.name }}}
+                .takeIf { extension.ignoreSubprojects }
+
+            ignoredSubprojects?.let {
+                extension.ignoredProjects.addAll(it)
+            }
+
             val ignored = extension.ignoredProjects
             val all = allprojects.map { it.name }
             for (project in ignored) {