1. The relationship was examined between four measures of lake productivity [total phosphorus (TP) and chlorophyll a (Chl a) concentrations, zooplankton density and biomass and growth in length and weight of age-0 yellow perch in ten central Alberta lakes. 2. In these lakes, average summer TP and Chl a levels were in the range 11-51 and 1.4-19.5-mu-g l-1, respectively. The interaction of TP and Chl a could explain 61% and 57% of the variance in total length and wet weight, respectively, of age-0 yellow perch sampled at the end of August. 3. The ability to predict first year fish growth from lake productivity is strongest at low levels of productivity (TP < 35-mu-g l-1). In the lakes studied, fish community structure is more complex at high levels of productivity (TP > 35-mu-g l-1), and more data on complex community level interactions seem necessary to predict fish growth in these systems.