This study evaluated alternative methods of land preparation for maize production on small farms in Western Province, Kenya. Human, oxen and tractors were the three sources of power. The crop production is dependent on rainfall, and timeliness of operations is critical. To ensure optimum yields 1 farmers in this area need to ready the available acreage for maize planting soon after the rains begin. An effective method of land preparation to improve labour productivity is desirable. Data were obtained from the Integrated Agricultural Development Program (IADP) records for 1977 and 1981 for Western Province, together with an additional sample of 40 farmers selected in 1981 from the same province. Based on the level of mechanization in land preparation, farms were categorized into those using: 1. the hoe, 2. owned oxen, 3. hired oxen, and 4. hired government or private tractor. Typical labour utilization profiles indicated that those not using the hoe for land preparation used fewer mandays of labour for that task but subsequently employed more labour to perform all the other necessary operations on the readied land. The proportion using owned oxen for ploughing increased from 25% in 1977 to 43% in 1981. Drudgery involved in hoeing was a factor facilitating the adoption of oxen-ploughing. Production function and covariance analyses showed that those owning oxen achieved higher yields of maize than those hiring oxen or tractors. Those using hoes had the lowest yield as well as the lowest labour productivity. Net cash income per acre was highest for oxen owners (Kshs. 580), but lowest for those hiring private tractor (Kshs. 200). Using owned oxen was more profitable than either hoeing or hiring oxen or tractor for ploughing. The main conclusion of the study is that oxen ploughing provides a viable way to increase the crop acreage and improve timeliness, yields and incomes in the specific region considered. Labour productivity is increased and the total labour requirement for maize production is maintained. Farmers who are willing but unable to invest in improved animal draught equipment should receive government assistance. Public support for tractor hiring service should be deemphasized, and diverted to alternative programs.