We studied the morbidity associated with steel needles used for intravenous therapy in adults with hematologic malignancy. Of 148 needles, 52 (36.1%) produced local inflammation, increasing with placements exceeding 24 hours, use of dextrose-containing infusate or intravenous antibiotics, granulocytopenia, and local infection. Eight needles (5.4%) caused local infection and three (2.1%) caused septicemia. Of nine bacteremias occurring in the 43 study patients, none of the five caused by Gram-negative bacilli, but three of the four caused by staphylococci, originated from steel needles. Five of eight local infections and all septicemias occurred with placements exceeding 72 hours (P = .016); each patient with septicemia was granulocytopenic. Intravenous steel needles are a major source of morbidity in patients with granulocytopenia or who are otherwise immunologically compromised. The insertion site should be routinely rotated at least every three days. Nosocomial staphlococcal bacteremia in granulocytopenic patients is likely to be due to an intravenous needle or similar device used for vascular access.