Forty-eight patients with recurrent adenocarcinoma of the ovary were treated with taxol and granulocyte colony stimulating factor (G-CSF), with a target taxol dose intensity of 250 mg/m2 every 3 weeks (83.3 mg/m2/week). We have assessed the patterns of granulocyte and platelet toxicity seen in this cohort. Individual patients received up to nine cycles of therapy. Criteria for entry onto protocol included good end organ function, good performance status and the absence of substantial co-morbid disease. Mean taxol dose intensity was 79.0 mg/m2/week for the whole cohort and did not diminish with increased duration of therapy. Granulocytopenia and thrombocytopenia were well controlled, with the average duration of platelet and neutropenic nadirs being less than 1 day for all cycles. There was no evidence of cumulative toxicity for granulocytes nor platelets, for up to eight cycles of therapy. We conclude that taxol, when given with G-CSF support, can be safely administered in a dose-intense fashion for multiple cycles of therapy, without cumulative bone marrow toxicity.