The technical efficiencies of New York dairy farms were estimated using a frontier production function. The average farm was 69 percent efficient. Individual farm efficiency was regressed on variables not considered inputs to explain why a farm was not on the frontier. Favorable location in the state and larger size (cows) as proxies for technology lead to greater efficiency. Participation in the Dairy Herd Improvement Cooperative and use of mail-in computerized records as proxies for management result in a reduction in efficiency. However, only 9 percent of variation in farm efficiency could be explained.