The case for promoting export-oriented cash crops in Africa has generally been based on their direct potential contribution to agricultural productivity and small farmer incomes. A relatively neglected avenue of research concerns the synergistic effects that cash cropping can have on other household activities, including food production. The conventional view that cash crops compete with food crops for land and labour neglects the potential for cash crop schemes to make available inputs on credit, management training, and other resources that can contribute to food crop productivity, which might otherwise not be accessible to farmers if they did not participate in cash crop programs. This article builds on previous research by hypothesising key pathways by which cash crops may affect food crop activities and empirically measuring these effects using the case of cotton in Gokwe North District in Zimbabwe. Analysis is based on instrumental variable analysis of survey data on 430 rural households in 1996. Results indicate that_.after controlling for household assets, education and locational differences-households engaging intensively in cotton production obtain higher grain yields than non-cotton and marginal cotton producers. We also find evidence of regional spill-over effects whereby commercialisation schemes induce second round investments in a particular area that provide benefits to all farmers in that region, regardless of whether they engage in that commercialisation scheme. The study suggests that the potential spill-over benefits for food crops through participation in cash crop programs are important to consider in the development of strategies designed to intensify African food crop production. © 2002 Elsevier Science B.V. All rights reserved.