Using a nationwide survey of rice growing farmers in Uganda, this study examined how farmers grow rice under rainfed conditions in various agro-climatic zones, and how rainfed rice cultivation performs in terms of yield, and what factors determine the level of rice yield. The study found that Nerica 4 and Supa were the two major varieties planted by rainfed rice farmers, the former in upland and the latter in lowland. High seeding rate, low fertilizer-chemical application and high labor intensity characterized rainfed rice cultivation in Uganda, though distinct regionality existed in fertilize-chemical application and labor intensity. The high marketed ratio of rice produce also characterized rice farming. The estimation of yield functions revealed that rainfall, the amount of seeds and fertilizers applied, lowland and small farmers were positive determinants of rice yield per hectare, that the potential for high yield existed in western regions of the country, and that there were some minor lowland rice varieties that performed better than popular Nerica 4 and Supa. The estimation also revealed that rice plots under the traditional tenure systems yield less, and those under the leasehold system yield more, than those under the formalized freehold and private mailo systems.