An automated continuous flow analysis for milk protein utilizing ultraviolet spectroscopy resulted in a correlation coefficient of 0.972 and a standard estimate of error of 0.082 percent protein when 30 samples were compared with the acid orange 12 dye binding method. Milk was solubilized in 95-105 volumes of acetic acid using the Technicon Auto Analyzer II and measured for absorbance at 274 nanometers. No deviation from the standard method due to mastitis and varying milk fat concentration was observed. A theoretical model indicated a possible standard estimate of error 0.059 percent protein due to inter- and intra-breed variation in milk protein fraction distribution. Potassium dichromate and other preservatives interfered with the results.