While anti-trafficking actors have long recognized the importance of measuring, evaluating and learning (MEL) from the multiple and evolving counter-trafficking efforts, there has not been systematic investment in MEL or a consolidated or shared approach to MEL practices and tools that can be used to inform the anti-trafficking sector more broadly. As a consequence, counter-trafficking programmes do not routinely draw on the significant amount of knowledge accumulated from multiple responses to date. This can limit the potential effectiveness of programmes, as well as the ability of evaluation to identify and report on programme outcomes. In an effort to reflect more systematically on the state of evaluation in the sector and to develop a way forward, this paper seeks to construct a common framework for aligning goals, defining and assessing progress, and building a robust and shared evidence-base of effective anti-trafficking programmes and practices. It suggests a road map for capturing and using knowledge accumulated in the sector and beyond, guiding and growing effective interventions, monitoring their progress, evaluating their results and compiling evidence of “what works” in countering human trafficking.