A study was carried out to estimate and analyze the profitability and resource use efficiency of lentil production in Sultanpur district of Uttar Pradesh. Using a pre-tested questionnaire, primary data and information were collected from 100 lentil producing farmers, categorized in 68 marginal, 20 small and 12 medium farmers were chosen from the five villages in the Kurebhar block of the Sultanpur district. The study revealed that the B: C ratio in lentil production was higher in medium farmer (1.19) due to increased production. Return to scale was found to be increasing in lentil production and Marginal Value Product were more than one in all the cases except few which indicate the further chance of investment on variable inputs to get the additional income. To get the maximum profit from lentil production using improved seed, input use in land preparation, threshing, and post-harvest should be increased while decreasing the amount of other inputs.