We treated nine patients in first remission from AML with rhIL-2. The toxic effects of rhIL-2 infusion were, malaise, pyrexia, and hypotension, which resolved rapidly on cessation of rhIL-2 infusion. No patient required transfer to an intensive care unit. Following rhIL-2 infusions patients developed eosinophilia, and a modest lymphocytosis, involving both NK cells, and T lymphocytes. Relapse occurred in six patients at a median of 39 weeks from remission. A particular concern was rapid relapse in the two patients with AML FAB type M5. There was no survival advantage from rhIL-2 treatment when compared to a similar group of chemotherapy only treated AML patients from this institution.