The effects of meal and body sizes on gastric evacuation (GE) of brook trout Salvelinus fontinalis (Mitchill, 1814) were determined following group feeding instead of feeding individually maintained fish. The GE experiments included small (ranging from 64.75 to 69.72 g) and large fish (ranging from 161.59 to 170.95 g). Fish in each size group was fed with three different meal sizes under similar conditions. The stomach contents were then recovered at predetermined postprandial times by serial slaughtering. The square root model adequately described the course of GE in S. fontinalis independent of meal size. The estimates of mass and length exponent obtained from S. fontinalis fed individually are in line with the present estimates. The result of this study would facilitate the planning and management of feeding regimes for S. fontinalis to minimise food waste and optimise growth.