In this paper we suggest that low labour availability on part-time farms may limit part-time farmers’ choice of production enterprises, and as a consequence those farmers may be forced to engage in less profitable enterprises. This proposition is illustrated by a conceptual framework based on the assumption that products with high returns to labour are labour intensive. An empirical analysis for the period 1996- 2004 based on aggregated yearly data from the Swiss Farm Accountancy Data Network (FADN) did not fully confirm the proposition. This may suggest the existence of a joint determination of the choice of production enterprise and of the choice to work off the farm. In addition, our assumption that highly profitable enterprises are labour intensive may not hold for specific products or contexts.