Replacing boards of education conceived during the Progressive Era with mayoral control has been a popular reform strategy in urban districts such as Boston, Chicago, and New York City. A thorough review of the extant research, however, shows little evidence regarding its impact on governance, management, school organization, or teaching and learning. Looking beyond the K-12 sector suggests that there is some reason to believe that appointed boards can be more effective than elected ones at pursuing shared ends and resisting short-term political pressure. This analysis explains the key political and organizational claims for and against mayoral control and considers the implications for governance reform. In the end, the author concludes that mayoral control is an uncertain bet and poses potential long-term problems but--if designed thoughtfully--holds promise for deeply troubled urban school systems. (Contains 2 notes.)