This paper investigates the efficiency of organic milk farms in Germany based on data from 1994/95 to 2005/06. Five inputs and one output are analyzed by means of a stochastic frontier production function, allowing for heteroscedasticity and technical effects. The selection of determinants of technical efficiency includes 5 groups of indicators. The analysis is focused on the impacts of farm support of organic farms and of regional factors, that can influence technical efficiency. The results show, that the agri-environmental payments show a negative effect on efficiency. Farms, which receive investment aid, show lower efficiency scores. Finally, the implication for agricultural policy are discussed.