The intention of this study was to assess the technical efficiency of farmers in sunflower production in Chemba District. Specifically, the study determined Technical Efficiency of sunflower production in the study area, estimated the level of responsiveness (elasticity) of yield with respect to the factor inputs and examined the factors affecting the technical efficiency in sunflower production. The study used stochastic production function model in the analysis to specify technical inefficiency effects of socioeconomic variables. It applied Maximum Likelihood Estimation (MLE) technique using cross sectional data collected from 92 randomly selected sample farmers in two villages of Paranga Ward. The MLE results revealed that off farm income and labour man days are the major factors influencing positively changes in the sunflower output. The effect of land area on the output is positive and the coefficient is found to be significant, implying the economies of scale. The test result indicates that there is inefficiency in the production of sunflower in the study area. The relative deviation from the frontier due to inefficiency is 39 %. The average estimated technical efficiency for smallholder farmers ranges from 7% to 92% with a technical efficiency mean of 61%. The analysis also reveals that famers sex, extension service, and farmer’s organization and off farm income are the major socioeconomic factors that significantly influenced farmers’ technical efficiency and sunflower output at 10%, 1% and 5%, respectively. The implication of the study is that technical efficiency in sunflower production in the study area could be increased by 39% through better use of available resources, given the current state of technology. The study identified the challenges facing sunflower production which include; trainings, organizations, lack of credit facilities, cost of inputs and plant diseases. The government is advised to improve farmers training to acquire necessary and adequate knowledge on sunflower production techniques, periodically organize training workshops for sunflower farmers on associations to facilitate farmers acquire market and production information and focus on provision of low interest rate credit for purchase of farm equipment and inputs.