We compare productivity and technical efficiency of organic and conventional dairy farms in the United States. We address self‐selection into organic farming by using propensity score matching and explicitly test the hypothesis that organic and conventional farms employ a single, homogeneous technology. Utilizing the 2005 Agricultural Resource Management Survey on Dairy Costs and Returns Report (ARMS) data, we reject the homogeneous technology hypothesis and find that the organic dairy technology is approximately 13% less productive. However, we find little difference in technical efficiency between organic and conventional farms when technical efficiency is measured against the appropriate technology.