This article investigates contribution analysis, an analytical tool invented by John Mayne, from both a theoretical and an operational perspective. Despite the substantial attention that contribution analysis has received, few studies appear to have applied it in practice. The article discusses the broadened scope of contribution analysis by analyzing its theoretical and methodological tenets, and examines its practical applicability in relation to two evaluations. The authors find that contribution analysis has much to offer the current theory-based evaluation landscape, but that further elaboration of the theoretical and methodological framework of contribution analysis is also needed.