Assessment of the response of fish populations to contaminants usually involves measurement of indicators of exposure or effects, but rarely do biomonitoring studies incorporate a mixture of endpoints that include both types of indicators. Our integrated bioindicator approach involves monitoring a suite of selected exposure and effects indicators at several levels of biological organization from the biomolecular level to the community level. Measurement of these selected biological variables permits early detection of environmental problems and provides insights into causal relationships between contaminant exposure and the effects that may be ultimately manifested at the population and community levels. This approach was applied to fish populations that inhabit streams receiving chronic inputs of contaminants including PAHs, PCBs, heavy metals, and chlorine. Indicators such as detoxification enzymes and DNA damage have provided direct evidence of contaminant exposure, whereas indicators related to lipid metabolism, histopathology, and general bioenergetic condition have reflected effects at both the suborganism and organism level. This bioindicator approach is an effective technique to assess the integrated effects of contaminant stress on fish.