Abstract.-The objectives of this study were to determine the growth and diet of two coexisting populations of yellow perch (Perca flavescens) and white sucker (Catostomus commersoni) in order to assess potential axes of competition between the two species. Perch in both Little Bear Lake and Douglas Lake were "stunted", with 4-year old perch averaging less than 130 mm in length. The diet of young-of-the-year perch shifted from zooplankton to benthos in July. Adult perch shifted back to a diet of zooplankton during the second summer of life. Suckers initially fed on zooplankton, but quickly shifted to a diet of benthos. The low diet overlap observed may be an indication of little competition between the two species, or it may indicate depletion of benthos by sucker predation to the point where perch are competitively excluded from utilizing this resource.