Bronchiolitis obliterans organizing pneumonia (BOOP) is a rare condition that affects oncological patients, often during or after chemotherapy, and can easily be mistaken for lung metastases. BOOP should be taken into consideration in cases when patchy nodular infiltrates with uncertain behavior appear in the lung; these infiltrates are often unresponsive to treatment with antibiotics. We report a case in which a patient treated for transitional cell bladder carcinoma with surgery and adjuvant chemotherapy developed multiple bilateral pulmonary nodules one month after the end of treatment.