The pallid shinerNotropis amnis, a rare minnow with an unknown life history, was collected from the Kankakee River, Illinois, over a 9-year period (1978–1986). The total length (L, mm)-weight (W, g) relationship for 88 specimens was log10W= –4.97 + 2.87(log10L). Condition factors (K= 105W/L3; mean, 0.69; range, 0.53–0.83) for specimens collected in July and August showed no trend by size and were lower than those of specimens collected in November. The annual catch per unit effort of juvenile pallid shiners (≤36 mm TL) was positively correlated with minimum flows in May and June, and negatively correlated with March air temperatures. The total catch was positively related to March maximum flow. Habitat suitability curves indicate that this species occurs in shallow areas with little or no current velocity and in moderately clear waters that are average in pH and warm and well oxygenated in summer. Juvenile pallid shiners occurred in shallower and more turbid waters than adults. Pallid shiners were associated with 45 other fish species. A cluster analysis, based on habitat and water quality variables associated with cyprinids, indicated that both juvenile and adult pallid shiners were found in conditions most similar to those of the bullhead minnowPimephales vigilax.