Research has identified a wide range of factors that affect evaluation use but continues to be inconclusive as to their relative importance. This article addresses the complex phenomenon of evaluation use in three ways: first, it draws on recent conceptual developments to delimitate the examined form of use; second, it aims at identifying conditions that are necessary but not necessarily sufficient for evaluation use; third, it combines mechanisms of evaluation use, context conditions, and actor perceptions. The study reported here examines the use of 11 program and project evaluations by the Swiss Agency for Development and Cooperation (SDC). The article makes use of qualitative comparative analysis (QCA), a method that is well suited to the study of context-bound necessity. It is concluded that the analysis of conditions that are necessary to trigger mechanisms of evaluation use in certain contexts is challenging, but promising to face the complexity of the phenomenon.