Abstract
Based on cross section data of 30 Oyster mushroom farms in Dong Ha city, Quang Tri province, this study estimated their technical efficiency level by using output-oriented Data Envelopment Analysis (DEA). The empirical results indicate that Oyster mushroom farms should expand their current level of output from 9 to 17% to be efficient. Moreover, it also reveals that technical inefficiency of Oyster mushroom in Dong Ha city, Quang Tri province was mainly due to scale inefficiency. Most of farms should increase their current scale to improve their technical efficiency.