We use new data from rural and semi-urban Thailand to examine how fi- nancial constraints affect who becomes an entrepreneurer and how existing busi- nesses are run. The new data allow us to control for both household and firm characteristics. In addition, the data were collected from two distinct geo- graphic areas in Thailand. This distinction allows us to contrast the impact of financial constraints in the Central region, where household wealth is rela- tively high and financial markets are comparatively well developed, with their impact in the much poorer and more remote Northeast. The analysis uses non- parametric and reduced form techniques. The results indicate that financial constraints play an important role in shaping the patterns of entrepreneuship in Thailand. In particular, wealthier households are more likely to start busi- nesses. In the Central region, wealthier households are also more likely to invest more in their businesses and face fewer constraints. In addition, entrepreneurial talent plays an important role in facilitating business start-ups in the North- east and is associated with higher investment levels in both the Northeast and the Central region. We also provide evidence that financial constraints place greater restrictions on entrepreneurial activity in the Northeast compared to the Central region. In addition, there is some intriguing evidence that the largest lender in rural and semi-urban areas has a greater impact on entrepreneurial activity through selection rather than through lending.