Municipal governments have employed a variety of strategies to address their ongoing revenue crises throughout the past several decades. One such strategy that has been employed with great consistency is the use of intergovernmental revenues (IGR). Given this trend, coupled with the fact that we know little about the dynamics of IGR, this paper presents one of the first multi‐year examinations of its use at the local level. Using data from 76 villages and cities in Cook County, IL (greater Chicago) for 1996–2000, we examine IGR use from the perspective of revenue diversification. The analysis indicates that during this period, local governments in Cook County (1) diversified their own‐source revenues and decreased dependence on the property tax; (2) maintained a consistent dependence on IGR; and (3) diversified and significantly altered their IGR structures. We also examine the demographic and organizational correlates of IGR diversification, and find it to be unrelated to characteristics such as population, property tax base, professional administration, and organizational capacity. As a result, we conclude that IGR diversification is a strategy that ought to be considered by all municipalities regardless of size or structure.