In four patients, a woman aged 85 and three men aged 33, 42 and 70 years, clozapine-induced agranulocytosis was diagnosed. In three patients the white cell counts were not performed as they should have been. Two patients were treated for their agranulocytosis with granulocyte colony-stimulating factor (G-CSF; filgrastim). Two patients were not treated. The literature concerning clozapine-induced agranulocytosis and its treatment with growth factors consists of only a few case reports. Therefore a definite conclusion about the efficacy of the treatment for this particular indication is not yet possible.