Fish cage culture is one of the systems of fish farming which has been considered in many countries including Iran, due to its high advantages. Purpose of any economic activities is to maximize profits. Considering the facilities and constraints in the agricultural sector of Iran's economy, the most appropriate way to increase the production and income of farmers is to use of optimal and proper level of production factors. The aim of this study is to evaluate the total factor productivity and efficiency of fish cage farms in Mazandaran province. Required data were collected through interviews and a detailed questionnaire. Based on the results, the total factor productivity index of 4 out of 9 farms was less than 1 and the average of this index was 0.998. On the other hand, the averages of technical, allocative and economic efficiency were 0.884, 0.725 and 0.645, respectively. The results showed that technical efficiencies of three farms were equal to one, and the allocative and economic efficiency of just 1 out of 9 farms was equal to one. Inefficiencies of farms in use of inputs were too drastic that if the cost minimizing input quantities had been used and the proper management had been applied, they would have been able to achieve the current level of their productions at 40% less cost. Given the emergence of fish cage culture in Iran, it is suggested that successful farms be encouraged by incentive policies to transfer their experiences to other farms in order to improve productivity and efficiency. This can be done through training courses using well trained instructors and successful farmers.