Production and financial impacts of recombinant bovine somatotropin (rbST) adoption are assessed using a survey of U.S. dairy operations and a model that corrects for self-selection bias. A substantial increase in milk production per cow is associated with rbST adoption, but large estimated financial impacts are not statistically significant. Substantial variation in the net returns of rbST adopters may be related to the management-intensive nature of rbST.