In 1993, we conducted an amphibian-vocalization survey in the Mullica River basin and compared the composition of anuran assemblages in the eastern (Wading River system) and western (Mullica River system) portions of the watershed.  The western Mullica River system was characterized by more extensive altered land (developed and farmed land) compared to the Wading River system. Degraded waters, characterized by elevated pH, specific conductance, and nitrate-nitrogen concentrations, were more frequently encountered in the Mullica River system.  We found differences in the distribution of individual anuran species and species assemblages between the two stream systems.  Six native-Pinelands species, the Pine Barrens treefrog (Hyla andersonii), carpenter frog (Rana virgatipes), green frog (Rana clamitans melanota), southern leopard frog (Rana utricularia), northern spring peeper (Pseudacris crucifer), and Fowler’s toad (Bufo woodhousii fowleri), were widely distributed.  Spring peepers were found more frequently in the Mullica River system.  Four non-native Pinelands species, including the bullfrog (Rana catesbeiana), pickerel frog (Rana palustris), northern cricket frog (Acris crepitans crepitans), and gray treefrog (Hyla versicolor), were heard only in the Mullica River system.  Bullfrogs were found more frequently at sites adjacent to developed or upland-agricultural land, whereas carpenter frogs were more closely associated with unaltered sites.  Pine Barrens treefrogs occurred more frequently in off-stream ponds compared to on-stream impoundments, whereas both carpenter frogs and bullfrogs occurred more frequently in impoundments.  Pine Barrens treefrogs and carpenter frogs were generally absent at sites where bullfrogs occurred.  Leopard frogs occurred infrequently at bullfrog sites.  Results of the survey suggest that on-stream anuran assemblages located in forest land may be more vulnerable to human-related impacts than off-stream pond communities found in a similar Pinelands landscape setting.