Paclitaxel has undergone a remarkable evolution of schedule and dosage based on observed schedule-dependent toxicity and consequent improvement of therapeutic index. A weekly schedule of administration was originally developed to exploit opportunities for radiation synergy and was subsequently explored without radiation to evaluate the potential for reduced toxicity. Three weekly schedules have emerged: paclitaxel 50 mg/m(2)/wk with concurrent radiation, paclitaxel 80 to 90 mg/m(2)/wk as a dose-dense schedule without radiation, and paclitaxel 150 to 175 mg/m(2)/wk as a dose-intensive schedule. The efficacy of these schedules, their integration as combination treatment with chemotherapy and nonchemotherapeutic agents, and their role are the subjects of substantial investigation.