While professional development has been emphasised in many countries, few comparative studies have examined the degree of teachers' participation in professional development and its effect on teachers. Using the TIMSS 2007 data, this study analyses to what extent teachers participated in professional development in 50 TIMSS countries and examines the relationship among high-quality teachers' professional development, teachers' beliefs, attitudes and job satisfaction. The study found that the extent to which teachers have participated in professional developmental activities was surprisingly low. In particular, teachers in 47 countries have rarely participated in active learning. The study also found that high-quality teacher professional development was significantly associated with greater job satisfaction, higher expectations for student performance and more positive attitudes in teachers concerning their implementing the school's curriculum. Policy implications for professional development are discussed.