The objective was to determine whether calmodulin was present in bovine milk with high SCC. A highly specific antibody against calmodulin was developed in rabbits and affinity purified. Enzyme-linked immunoassays were used to determine the presence of calmodulin in the whey and casein fractions in milks with SCC ranging from less than 50,000 to greater than 1,000,000. Percentages of total protein and casein were determined. Calmodulin was detected in some casein fractions regardless of level of SCC. In the whey fraction, calmodulin was positively correlated with increased SCC. Calmodulin may be released into the milk as a result of the elevated proteolytic activity, which is evident in mastitis or as a result of leakage from the serum. This provides further information on the cellular and biochemical changes that occur in the diseased udder. Total protein increased with the increase in SCC while there was an inverse relationship of SCC to the percent casein.