The objective of this paper is to apply the stochastic production frontier methodology to a survey database collected in northern Vietnam. Our study finds that the average technical efficiency of tea production is only about 41 %. Among extension policy measures available to farmers, only training on production inputs has an improving impact on technical efficiency. Other features of policy have no significant effect, contrary to the expectation. The adoption of the oldest variety “Trung-Du” is not a source of inefficiency while the effects of other new varieties are insignificant. The results indicate that there is a great potential for improving production efficiency in the region of the study.