This study was aimed to determine the gastric evacuation (GE) in brook trout (Salvelinus fontinalis) fry and to estimate the effect of body mass on their GE rate (GER). A group of small and large sized S. fontinalis fry (ranging 0.39-0.66 and 0.76-1.46g) was fed with commercial pellets under similar conditions to avoid the ingress of any other variable such as temperature and dietary energy density. Their stomach contents were sampled at predetermined postprandial times, and were dried at 60 degrees C to constant weight. The course of GE in both sizes of S. fontinalis fry was best described by the square root model. The relationship between GER and body mass was then determined by a power function of fry mass that can be summarized by the equation (g h-1), where St is current stomach mass (g), M is fry mass (g), and t is time (h). The course of GE in S. fontinalis fry is similar to that previously reported for adult S. fontinalis.