A phase II trial of vinorelbine and low dose prednisone in hormone-refractory metastatic prostate cancer was conducted in order to investigate its safety, efficacy and impact on quality of life. Vinorelbine was administered at the dose of 25 mg/m(2) i.v. weekly for 12 weeks and then biweekly, along with 10 mg of daily oral prednisone until time of progression. Fourteen patients, median age of 74 years, were treated. The treatment was generally well tolerated with leukopenia and anemia as the major side effects. One patient achieved partial remission and eleven remained with stable disease. One of the eleven patients with stable disease had a dramatic PSA response from 1000 to 236 ng/ml; seven of these progressed after week twelve when vinorelbine was given biweekly. PSA response occurred in 5 of 14 patients. The median time to progression was 28 weeks and the median survival was 17 months. Nine out of the 14 accrued patients were evaluable for quality of life assessment. Five of them improved, three remained unchanged and two had a slight worsening. Four patients had improvement in pain control and fatigue. Our preliminary data suggest that the combination of vinorelbine/prednisone has modest activity in metastatic prostate cancer with a very favorable toxicity profile and is very well tolerated in this group of elderly patients.