The objective of this article is to evaluate the efficiency in the urban transportation service in the city of Bahia Blanca, Argentina. The estimations where based on the stochastic border method applied to a production function with panel data for the 2007-2014 period. Results indicate that the average efficiency level didn´t vary significantly during the analyzed period. At the same time, monetary transfers and line concentration allowed to maintain the business profitability without this translating necessarily in efficiency gains.