During a 9-year period, 204 infants younger than 12 months of age had 294 Broviac central venous hyperalimentation catheters inserted. Fifty-nine adult-size and 235 infant-size Broviac catheters were used. Catheter insertion was via the saphenous vein (267), external jugular (7), internal jugular (16), cephalic (2), and transthoracic right atrial veins (2). General anesthesia was used for all internal jugular, but for only 11 saphenous catheters. Catheter function ranged from 6 to 925 days (mean, 112 days). Forty-four infants had malabsorption syndromes, 36 had short bowel syndrome, 38 had intractable diarrhea, and 86 required nutritional support for a variety of other conditions. Fifteen of the 204 infants developed inferior (10) or superior vena caval thrombosis (2), or both (3). Thrombosis occurred in 13 of the 267 infants with saphenous catheters (4.9%), and five of the 25 with jugular or cephalic venous catheters (20.0%). Obstruction to normal catheter infusion was the first sign of caval occlusion. Transient mild leg edema (4) and prominent venous pattern over the legs (3) were present with inferior vena caval (IVC) occlusion, but no patient had renal vein obstruction or died as a direct result of this condition. Each of the two patients with superior vena caval (SVC) occlusion experienced mild to moderate edema and venous suffusion of the head and upper extremities, and one developed a pleural effusion. Each of the three infants with combined superior and inferior vena caval thrombosis died from pulmonary insufficiency within six months after SVC occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)