Chemotherapy that targets microtubular trafficking induces responses in most patients with prostate cancer. One regimen under investigation is the combination of docetaxel and estramustine. We report on 2 patients with androgen-independent disease who received continuous weekly docetaxel and estramustine and who died of irreversible respiratory failure. The clinical, pathologic, and radiographic data support drug toxicity as the likely etiology. Inclusive of these patients, only 17 cases (10 fatal) of acute pulmonary toxicity using docetaxel have been reported, despite its wide use. We recommend that patients receiving weekly docetaxel, with or without estramustine, have frequent treatment breaks and be evaluated with computed tomography of the chest every 8 weeks.