Many different management measures are available to control mastitis, a very costly disease in the dairy sector. The objective of this paper was to evaluate the costs and efficacies of 18 of these management measures, for contagious and environmental pathogens, and their effect on bulk tank somatic cell count (BTSCC) and incidence of clinical mastitis (CM). To determine the efficacies for these management measures, literature data and expertise were combined using Monte Carlo expert evaluation analysis. The effect of management measures varied with the incidence of CM and BTSCC, as well as for environmental and contagious problems. On average, postmilking teat disinfection was found to be the most effective measure in all situations. All management measures had large uncertainty around the most likely value. Results of a data envelopment analysis showed that 4 of the management measures included formed the best-practice frontier (the most cost-efficient measures): keeping cows standing after milking, rinsing clusters after milking a clinical case, using a separate cloth for all cows, and wearing milkers’ gloves. Of the top 25 management measures (the 18 base management measures including levels of compliance), 8 were measures with 100% compliance; the others were sublevels of these measures with compliance varying between 25 and 100%. A lower hourly rate of the farmer did not influence management measures from the best-practice frontier, but had some effect on the efficiency scores of the other management measures.