Five patients with non-cytotoxic drug-induced agranulocytosis were treated with recombinant human granulocyte-colony-stimulating factor (rh-G-CSF). The drugs involved were dipyrone, captopril, clozapine and carbimazole. Bone marrow examination revealed a depleted granulopoiesis with normal erythro- and megakaryocytopoiesis. After discontinuation of the suspected drug, rh-G-CSF was administered daily at 5 microg/kg subcutaneously. The neutrophil counts were recovered between day 6 and 12 and patients were discharged from hospital shortly afterwards. Compared to data from the literature, the neutrophil recovery appeared to be faster than expected without the use of haematopoietic growth factors. In conclusion, rh-G-CSF at a standard dose of 5 microg/kg seems to be an effective treatment for drug-induced agranulocytosis.