Aim of this study is to determine technical efficiency and determinants of technical efficiency of rice farms in Kien Giang, Vietnam, based on a cross-sectional data collected in 2015 from 302 rice farmers in Kien Giang province. The Cobb-Douglas stochastic frontier production function, incorporating inefficiency effects was employed to analyze the data, using the FRONTIER 4.1. The results revealed that the technical efficiency was ranged 64.22-99.85%, average of 84.97%. Significant factors that were found to positively affect rice output per farm were area, phosphate fertilizer, and rice variety while seed and nitrogen fertilizer were negatively related to the rice output per farm. Significant determinants of technical efficiency were positively related to technical efficiency were gender, education attainment, farm size, training, membership of farmers’ association.