This article summarizes critical evaluation needs, challenges, and lessons learned in translational research. Evaluation can play a key role in enhancing successful application of research-based programs and tools as well as informing program refinement and future research. Discussion centers on what is unique about evaluating programs and policies for implementation impact (or potential for dissemination). Central issues reviewed include the importance of context and local issues, robustness and external validity issues, multiple levels of evaluation, implementation fidelity versus customization, choosing evaluation designs to fit questions, and who participates and characteristics of success at each stage of program recruitment, delivery, and outcome. The use of mixed quantitative and qualitative methods is especially important, and the primary redirection that is needed is to focus on questions of decision makers and potential adoptees rather than the research colleagues. (Contains 3 tables.)