Intracardiac fungal masses can develop following episodes of candidemia in premature infants with indwelling right atrial lines. We report the first premortem diagnosis and successful surgical removal of Candida-containing intracardiac masses in three premature infants. All had central venous lines and had been on systemic antibiotics prior to the development of candidemia. By echocardiography, two were pedunculated, solitary masses within the right atrium. Amphotericin B and 5-flucytosine for 21 to 42 days controlled the Candida sepsis, but the masses became increasingly mobile and did not decrease in size. In the third infant, large, irregular masses extended from the right atrium to the main pulmonary artery, and surgical removal was recommended 4 days after the start of antifungal therapy. In all three patients, the masses were nearly the size of the main pulmonary artery and presumably contained viable organisms. Removal was accomplished with the aid of cardiopulmonary bypass for two and inflow stasis for one infant weighing only 1,300 gm. The masses were filled with viable Candida organisms. All patients tolerated the operation well and have been followed up for 1 to 3.6 years without evidence of recurrent Candida infection. The case of a fourth infant, weighing 1,320 gm, is also reported. This infant had a bacteria-containing intra-atrial mass, which was removed successfully with the aid of inflow occlusion. This report documents the following points: (1) Echocardiography provides a noninvasive method of diagnosing the development of intracardiac masses and should be performed in infants who have had candidemia and a central venous line. (2) Prolonged systemic antifungal therapy does not appear to either sterilize or promote regression of the masses. (3) The masses can be safely removed, even in the premature infant, with either inflow stasis or cardiopulmonary bypass. (4) Surgical removal is an effective component of the treatment of infection in these infants.