Studies on efficiency changes in transition agriculture yield mixed results. This paper develops both a theoretical model and an empirical analysis of how distribution of efficiency scores changes with the various stages of transition. We use a unique set of representative farm survey data to calculate farm level efficiency scores, compare the efficiency distributions of different transition countries and correlate these with various indicators of particular reforms. Our study indicates that, in particular, general institutional reforms and reforms focused on market institutions and on reducing market imperfections in input and output markets have an important positive impact on farm efficiency.