Twenty patients with metastatic prostatic cancer were treated on an ambulatory basis with continuous 5-fluorouracil (5-FU) infusion 250-300 mg/M2 per day through a chronic indwelling central venous catheter. All patients had symptomatic, progressive disease despite previous standard therapies. Partial remission was seen in 2 of 20 patients (10%), stable disease in 9 of 20 (45%), and progressive disease in 9 of 20 (45%); mean duration of benefit in responding and stable disease patients was six months. Improvement in pain and ECOG performance status were seen in most of the patients in the responding and stable disease categories. Forty percent of the patients experienced no significant drug toxicity; treatment interruption was necessary for stomatitis in 6 patients (30%), hand/foot syndrome in 3 patients (15%), and diarrhea in 1 patient (5%). No significant myelosuppression or other significant organ toxicities were encountered. Continuous systemic venous infusion of 5-FU may provide significant palliative effect for some patients with symptomatic, refractory carcinoma of the prostate.