What are you trying to accomplish with this, instead of using Gradle’s parallel test execution? As far as I know, ParallelRunner has never left experimental stage, and no released version of JUnit is thread-safe. Besides, ‘JUnitCore’ and ‘ParallelComputer’ are only meant to be used by the party that’s in control of test execution (build tool, IDE). If you use it from a test, you essentially kick off your own inner test execution, and there is no way for the outer party to know about that. That’s why you don’t see anything in the Gradle report.