During last decade, the excluding efficiency of circle hooks for sea turtle has given positive and successful outcomes in Oaxaca, Mexico. The research seeks: 1) determine if the change of fishing gear provides positive benefits to local small scale longline fishermen, 2) estimate the benefit and cost functions, 3) determine the parameters variates and its influence in both models, and 4) estimate a Cobb-Douglas production function. Using unrestricted sampling with proportional assignment, 540 surveys were conducted through May to September 2015. Two benefit models were estimated (EE1-R1 and EE1-NR), the first one is restricted to boats using Selar rumenophthalmus, Ophioscion vermiculatus and Caranx caballus as bait, and the second model is unrestricted. Two models were also estimated for catch, the first (EC1-R1) includes boats using only longline, and the second (EC2-R2) restricted to boats using the bait species mentioned. For model EE1-R1 cost and income are statistically significant at 0.01%, showing elastic and inelastic elasticities respectively. For benefit model EE1-NR, significant variates at 0.01% are price, catch and coast distance. For EC1-R1 significant parameters are coast distance, catch weight and time (hours longline left in water). Significant parameters for model EC2-R2 are coast distance and number of caught fish. Finally, a Cobb-Douglas production function was also estimated, using fishermen as labor and hooks in longline as capital, the factor elasticities are inelastic and, lastly, the small scale longline fishery has decreasing returns to scale. Models highlights the importance of the use of bait species in Oaxaca´s small scale longline fishery.