Teliospores ofMelampsora pinitorquaRostr. were collected in the formation, overwintering and germination stages and observed by transmission electron microscope. Some information about their general ultrastructure is given, particularly concerning the cell wall, lipid bodies, mitochondria, ER, cytoplasmic vesicles, vacuoles, unidentified membrane formations, nucleus and germ tube wall. Some organelle changes occurring from the maturation to germination stage were observed.