In this paper, an attempt has been made to document the economic efficiency of mustard production in arid zone of Rajasthan. The forty farmers were selected each from simple random sampling method among the farmers using new technology (mustard variety Jai Kisan) as well as traditional technology for mustard crop. The results indicated that modern technology generated higher technical efficiency. The higher technical efficiency could be achieved due to efficient use of inputs. If the farmers used inputs efficiently, 22 per cent more yield could be obtained. Similarly, there is ample scope to increase the wheat and mustard production by nearly 20 to 25 per cent. This would lead to decrease in unit cost of production and increase the farm income.