This paper aims to estimate a translog stochastic frontier production function with panel data of 147 mixed Catalan farms in a five-year period. The mean output efficiency in the period analysed was estimated to be 62.3%. We added management variables to the traditional factors explaining farm efficiency, and found that fully integrated management based on reliable accounting information and comprising planning and control phases reveals to be a significant factor positively affecting farm efficiency. Farm efficiency levels were also found to be positively influenced by farm size, while rented and irrigated area influence negatively farm efficiency levels.