Purpose: To evaluate the new anticancer agent, docetaxel, with a novel mechanism of action in patients with non-Hodgkin's lymphoma International Working Formulation (IWF) A through H, to determine the response rate by histologic group and the toxicities of this agent in this population. Patients and Methods: Sixty-eight patients previously treated for non- Hodgkin's lymphoma with two prior cytotoxic regimens for low-grade and one prior regimen for intermediate-grade lymphoma were entered onto this phase II trial. Central pathologic review was required. Twenty-four IWF A to C and 31 IWF D to H patients with normal hepatic and renal function, performance status (PS) 0 to 2, and adequate hematologic function were eligible. Patients received docetaxel 100 mg/m2 intravenously over 1 hour without corticosteroid premedications every 3 weeks with weekly hematologic monitoring, and tumor assessment every 3 weeks for grade 3 or 4 hematologic toxicity, the docetaxel dosage was lowered to 75 mg/m2. Patients received a maximum of six cycles of therapy. Results: The major response rate was 13% (95% confidence limits, 3% to 32%) for IWF A to C and 16% (95% confidence limits, 5% to 34%) for IWF D to H; response durations ranged from 1.4 to 20 months. Time to response ranged from 1.3 to 2.8 months. Patients refractory to previous chemotherapy were less apt to respond to docetaxel, but the differences were not statistically different in this small sample size. Twelve percent of IWF A to C and 6% of IWF D to H patients discontinued treatment because of toxicity. The major toxicity was granulocytopenia (grade 3 to 4), which occurred in virtually all patients during the first course of therapy. Conclusion: This study confirms that docetaxel has limited definite activity in patients with non-Hodgkin's lymphoma and suggests that the previously reported responses with taxanes can not be attributed solely to the use of corticosteroid premedications.