The impact of selective forest harvesting on soil nutrient leaching, headwater stream chemistry and nutrient content of over- and understory vegetation was examined at the Turkey Lakes Watershed in central Ontario, Canada. Data was collected pre-harvest and during the initial five years post-harvest within four experimental catchments ranging in size from 4.6 to 66.4 ha. Basin treatments included selection-cut (29% basal area removal), shelterwood-cut (42% basal area removal), diameter limit-cut (89% basal area removal) and unharvested forest. For the first three years post-harvest soil percolate and stream nitrate and base cation concentrations in the diameter-limit catchment increased to a greater extent than in the selection or shelterwood treatments. Natural variation in soil properties across the basins influenced sulfate and organic anion concentrations in soil percolate and hence base loss from the soil. Post-harvest soil percolate nitrate and base cation concentrations were significantly related to the basal area of the forest overstory determined directly around lysimeter locations. There was increased uptake and nutrient storage in the understory community of the diameter-limit harvested basin when compared to the lower harvest intensities. Understory re-establishment was more strongly related to harvest-related soil disturbance than to canopy opening. There was a strong linkage between vegetation nutrient storage and drainage water concentrations. Nitrate and base cation concentrations in soil percolate and stream water in the diameter-limit treatment were lower than other harvest treatments and the undisturbed catchment four growing seasons after harvest.