Crop production in Semuto Sub County has experienced changes from traditional crops such bananas and robusta coffee to crops like vanilla and upland rice. In this dissertation, a comparative study of cash and food crop production from 1980 to 2002 in Semuto Sub County, Luwero District was conducted. The study specifically sought to identify the main traditional food and cash crops, area covered by them in the past and at present, factors responsible for the changing patterns in crop production, implications of increased cash crop growing on food security and on livelihoods of people. The primary data were collected using participatory rural appraisal and structured questionnaires. Field observations, in depth interviews, focus group discussions and secondary data supplemented the questionnaires. Secondary data were obtained from reports and other documents from various offices. A total sample of 162 respondents including the Luwero District Agricultural officer, Extension officer, Sub county and parish chiefs, local people and local leaders were consulted. Data collected was analyzed using the Statistical Package for the Social Scientists (SPSS). Descriptive statistics were used in the analysis.