Comparing enterprise size across countries is a key challenge in international development—SME definitions used in international development are often criticised as ineffective and a source of mistargeting of international development resources in the private sector. This study applies the International Finance Corporation definition of small and medium-sized enterprises (SME), commonly used in international development, and that proposed by Gibson and Van der Vaart (GV) (2008) to a set of enterprises in Africa to determine whether the two definitions capture similar underlying firms and enterprise attributes that practitioners would like to think of as worthy of international development support. The article finds a significant overlap: enterprises classified as SMEs simultaneously by both definitions. Indeed, 57% of firms in the sample qualify as SMEs under the two definitions. SMEs under the GV definition (but not the other) appear to face significant constraints in obtaining access to finance compared to those under the IFC definition (but not the other), and perform poorly in creating jobs relative to those under the IFC definition.