Short-run and long-run technical and allocative efficiencies were computed for 395 New York dairy farms using data envelopment or nonparametric procedures on 1990 Dairy Farm Business Summary data. The farms were, on average, more allocatively efficient in the short run than in the long run, but were more technically efficient in the long run than in the short run. Stanchion barns were as efficient as milking parlors, and milking more than two times per day did not increase efficiency.