The main objective of this paper was to evaluate the technical efficiency in 17 milk production farms in the region of Viçosa, state of Minas Gerais, during the period 1999-2002. These farms have received technical assistance from a program created by the Federal University of Viçosa and Nestlé. The technical efficiency was evaluated through the Data Envelopment Analysis (DEA) technique. The results obtained show that there are still a significant proportion of inefficient farms. It was also observed that the farms have become more homogeneous in their production characteristics which is probably due to the pattern of technical assistance adopted during the period analyzed.