It was our intention to verify if increases of granulocyte colony stimulating factor (G-CSF) dose were able to reduce treatment delays due to leukopenia in our weekly regimen of cisplatin (40 mg/m2), epidoxorubicin (35 mg/m2), 6S-leucovorin (250 mg/m2) and 5-fluorouracil (500 mg/m2), usually supported by G-CSF at a dose of 5 mu g/kg. Forty five patients with advanced gastric carcinoma (30 males and 15 females; median age 64 years) were randomized to receive three different doses of G-CSF (5, 8 and 10 mu g/kg) by s.c. injection. We did not observe any difference in the mean value of neutrophil counts at each of the 8 weeks of treatment; while we registered a higher incidence of severe neutropenia (< 500/mm3) in patients receiving higher G-CSF doses: two patients in the group at 5 mu g/kg, four in the group at 8 mu g/kg and seven in the group at 10 mu g/kg. Furthermore, low doses of G-CSF allowed a similar number of chemotherapeutic administrations in the eight study weeks. The results arising from our study do not seem to support the use of higher doses of G-CSF, at least in not such a weekly regimen.