Over the years, teachers and school leaders have engaged in some form of training beyond their formal preservice, university preparation programs. Whether referred to as in-service training, professional day, or staff or professional development, this activity normally had one purpose: to improve participant's knowledge or skills. With limited teacher time to attend in-service training and limited financial resources to pay for this training, districts are searching for training that provides returns on these investments in time and money: returns in terms of increased student achievement. In this article, the author discusses how to increase the chances that professional development will be transformed into increased student improvement by examining three issues: (1) Does professional development impact student learning?; (2) How can school leaders judge the effectiveness of their professional development program?; and (3) What professional development characteristics are linked to improved student learning? The author concludes that the right kinds of professional development for both teachers and school leaders can directly contribute to improved student performance. Schools can become advocates for investment in increased professional development by capturing evidence of its effectiveness to show a return in learning of their investment in time and money.