Solitary, large male breast cysts are extremely rare. They occur mainly in children up to the age of seven, with the maximum incidence in the first 21/2 years of life (Chumachenko, 1968). Pneumocystography and pneumomammography are very useful tools to diagnose cystic breast disease in females and to differentiate this entity from other breast diseases (Baraldi, 1935; Gross, 1952; Weshler et al., 1973). In males, the use of these diagnostic procedures has not been reported. In the present paper, we describe two cases of solitary breast cysts in males aged 11 and 35 in whom the diagnosis was established with the above mentioned procedures.