Over 100 years, urbanization has taken place along the Rouge River watershed of southeast Michigan, USA. To determine the impact(s) of urbanization on herpetofauna, species richness and distribution in 122 wetlands along 13.0 km of the urbanized Rouge River watershed were monitored from early spring to late fall 2003. Data were mapped using Geographic Information Systems (GIS). Both amphibian and reptile species richness were associated with wetland size and hydroperiod. The invasive plants Alliaria petiolata and Rhamnus cathartica were coincident with lower than average amphibian species richness. In spite of the number of herpetofauna being relatively low, this study identified hydroperiod and wetland size as important features that may contribute to amphibian and reptile species sustainability in this highly disturbed and fragmented urban landscape.