Test-driven development (TDD) is an accepted practice in the software development industry. Although computer science teaching programs have been slower to adopt test-driven practices, test-driven learning has been used in a number of universities with generally positive results. The use of test-driven learning at the high school level is less studied. We introduce and assess the benefits of using test-driven learning in a high school Advanced Placement (AP) computer science course. This course is a strong candidate for the introduction of TDD. The Java language used in AP computer science is well-supported by TDD tools, and the concepts of TDD show promise in helping students develop the ability to analyze problem statements and develop programs. Preliminary results indicate that students respond well to the use of TDD tools to complement other teaching techniques in AP CS.