This paper estimates profit efficiency and its determinants in small and medium-sized manufacturing enterprises in Spain. The stochastic frontier methodology and the model proposed by Battese and Coelli (1995) were used to determine the impact of the technological and environmental differences between these companies on their efficiency. The results indicate that the average profit efficiency of food SMEs is 49.37%. The results also reveal that company size, export orientation, government assistance and labour productivity are all positively related to the efficiency of food SMEs; age, however, is negatively related. Finally, the strategic implications of these findings are discussed. JEL classification: C33, D24, L66, M10, Keywords: Profit efficiency, Stochastic frontier, SMEs