Gamont of Hepatozoon canis was observed by light, phase contrast and transmission electron microscopies. In a thin blood film the gamont was contained within a pale-blue capsule in the leukocyte. By phase contrast microscopy, the gamont was seen to be surrounded by a contrasty substance. Transmission electron microscopy revealed the presence of a parasitophorous vacuolar membrane, two layers in the pellicle of the gamont and a fine fibril-like structure surrounding the parasitophorous vacuole.