A volumetric method in which the stomach contents are squashed to a uniform depth and the volume is derived from the area of the squash has been evaluated. The apparatus is simple in constiuction and the method applicable to a wide range of fish sizes. The overall error of the method may be as low as 3.5 % for well macerated material, though for hard bodied food animals the coefficient of variation may be up to 8 %. These volumetric determinations are not directly proportional to gravimetric measurements but logarithmic conversion curves are readily derived.