The study was aimed at estimating efficiency of rice farms in the Mekong Delta of Vietnam using data envelopment analysis (DEA) approach. In this regard, data for the crop year 2014 were collected from 400 rice farms. The findings showed that the average efficiency scores were 80.9 percent for technique, 90.7 percent for allocation, 73.4 percent for cost, and 83.2 percent for scale, respectively, of rice producers. There were very few farms (1.25 percent) which were fully allocative and cost efficient, suggesting that majority of the farms have potential to improve their efficiency in terms of technique, allocation, cost and scale. The primary cause of inefficiency in the rice farms was attributed to technique, implying that higher cost efficiency might be achieved by improving technical efficiency. Further, the regression results indicated that rice farm size, credit access, and training were found to have significantly negative effects on technical and cost efficiency of farms. Therefore, this study arrived at suggestion that the quality of credit access and training programs need to be upgraded for improving technical and cost efficiency of the farmers.