If inclusive business is to realise wide and sustained development impacts, it is likely to depend on crowding in of other public and private actors. Assessing the contribution of inclusive business to crowding in is difficult because the phenomenon usually only manifests after project completion, and the complex operating environment complicates the process of evidencing a link between intervention and outcome. With donors placing increasing emphasis on demonstrating impact, innovative approaches to assess crowding in are needed. This article presents an adapted form of process tracing to assess the contribution of inclusive business to crowding in. It reports on the contribution of CREATE, an inclusive agribusiness project, to the crowding in of malting companies in Ethiopia’s barley value chain. Though predominantly focusing on demonstrating a programme’s contributions to crowding in, the article offers suggestions for how this process tracing-based exercise may support the fostering of inclusive agribusiness practices more broadly.