This retrospective study was undertaken to investigate whether paclitaxel was associated with cumulative bone marrow toxicity in patients undergoing salvage chemotherapy for refractory ovarian cancer. Seventy-seven patients were treated with paclitaxel 135 mg/m2 every 21 days, with granulocyte-colony-stimulating factor (G-CSF) support as necessary according to standard criteria. The mean white blood cell nadir was significantly higher and the incidence of severe leukopenia (Gynecologic Oncology Group grade 3-4) significantly lower after ten cycles than after the first cycle for the entire study population (3.4 vs. 1.6 x 10(3)/mm3 and 29 vs. 77%, respectively) and the patients who received G-CSF (3.5 vs. 1.4 x 10(3)/mm3 and 33 vs. 89%, respectively), but did not differ significantly for the patients who did not require G-CSF (2.9 vs. 2.5 x 10(3)/mm3 and 40 vs. 59%, respectively). The mean hematocrit and platelet nadirs, as well as the incidence of severe anemia and thrombocytopenia, did not differ significantly after ten cycles from those after the first cycle for the entire study population and both subgroups. Thirty-two (42%) patients received G-CSF, each initiated within four cycles. The indications for initiating G-CSF support were febrile leukopenia (53%) and treatment delay (47%). The average duration of G-CSF support was 4.6 days, and did not increase significantly as the number of paclitaxel cycles increased. We conclude that paclitaxel was not associated with cumulative bone marrow toxicity in patients undergoing salvage chemotherapy for refractory ovarian cancer.