Given the proliferation of training transfer studies in various disciplines, we provide an integrative and analytical review of factors impacting transfer of training. Relevant empirical research for transfer across the management, human resource development (HRD), training, adult learning, performance improvement, and psychology literatures is integrated into the review. We synthesize the developing knowledge regarding the primary factors influencing transfer--learner characteristics, intervention design and delivery, and work environment influences--to identify variables with substantive support and to discern the most pressing gaps. Ultimately, a critique of the state of the transfer literature is provided and targeted suggestions are outlined to guide future empirical and theoretical work in a meaningful direction. (Contains 2 notes and 3 figures.)