Occupational licensing is intended to protect consumers. Whether it does so is an important, but unanswered, question. Exploiting variation across states and municipalities in the timing and details of midwifery laws introduced during the period 1900-1940, and using a rich data set that we assembled from primary sources, we find that requiring midwives to be licensed reduced maternal mortality by 6 to 7 percent. In addition, we find that requiring midwives to be licensed may have had led to modest reductions in nonwhite infant mortality and mortality among children under the age of 2 from diarrhea. These estimates provide the first econometric evidence of which we are aware on the relationship between licensure and consumer safety, and are directly relevant to ongoing policy debates both in the United States and in the developing world surrounding the merits of licensing midwives.