The cottage food processing industry in Thailand comprises mainly small-scale enterprises such as the 'housewives groups' that consist of a number of housewives who combine their food processing activities in a particular district or village. The effects of various factors on the performance of these housewives groups is assessed using survey data to estimate a stochastic input distance model. Our results show that membership of vertical strategic alliances at a high level is associated with higher levels of technical efficiency. Other factors positively influencing technical efficiency within these groups are the level of experience of group members, the ratio of workers to total members, government support, the community base of the group as opposed to private ownership, and the availability of funds to invest in business activities that have been derived from savings activities by group members. The ability of housewives groups to exploit cost complementarities by combining fruit and vegetable processing activities is tested by estimating scope and diversification economies for fruit and vegetable processed outputs. While diversification economies were found to exist, the more rigorous test for scope economies did not support their existence.