This paper investigates farm level technical inefficiency of production and its determinants in a sample of 150 citrus producing farms in Tunisia using a stochastic frontier production function approach applied to cross section data. Results indicate that technical efficiency of production in the sample of citrus producing farms investigated ranges from a minimum of 26.84% to a maximum of 97.98% with an average technical efficiency estimate of 86.23%. This suggests that citrus producers may increase their production by as much as 13.77% through more efficient use of production inputs. Further, the estimated coefficients in the technical inefficiency model indicate the positive effect on technical efficiency of the share of productive trees, the agricultural training, irrigation operations and the experience of farmer.