This article explores the process of learning from inter-organizational projects by SMEs. We analyse a sample of 1,500 SMEs to empirically develop a typology of different types of projects and conduct an in-depth comparative case study in each of the types. We find that 1) differences between project types influence the degree of project-based learning by SMEs, and 2) the mechanisms by which SMEs learn from projects can be unintentional, haphazard, and resemble learning by bricolage. These findings lead us to question the deliberate and pro-active nature of organizational learning that has been central to recent theory development.