While program experimentation targeting men has mushroomed in many parts of the world, operations research that examines the feasibility, acceptability, and impact of genderbased approaches has been limited. In response to this gap, the Horizons Program, together with partner organizations, is undertaking important programmatic research among young men in three countries. The research seeks to better understand the linkages between gender norms and HIV risk behaviors, and to determine whether the interventions that are developed using this information make a difference in the lives of young men and their partners. This issue of the Horizons Report describes emerging findings from studies in Brazil, Tanzania (page 7), and India (page 10).