e20688 Background: Pleural effusions are a common complication in cancer. All tumors, except CNS tumors, can produce pleural effusions. Pleural effusions are usually caused by direct tumor pleural involvement. Diagnosis is clinical and paraclinical. In cancer patients, in pneumonia absence, most of pleural effusions are malignant, regardless cytology results. Among different treatment modalities, chemical pleurodesis is the oftenest, but it is not etiologic nor physiologic. Chemotherapy in chemosensitive cancers is a good management approach. The objective of this study was measure systemic chemotherapy effectiveness in cancer pleural effusion after drainage and emphasize this method as treatment. Methods: Beginning 1/March/2001 and finalizing 30/July/2006, patients with chemosensitive cancers, malignant pleural effusions, no previous chemotherapy, KI > 80, life expectancy > 6 months, were included. Procedure: Chest X - ray, chest tube insertion for draining pleural effusion, systemic chemotherapy application, generally IV, tube remotion the day after ending chemotherapy, clinical and paraclinical follow up. No effusion reproduction minimum per six months. Effectiveness goal was 80% minimum. General statistic analysis was used. Results: 42 patients were studied, male: 38,09%, female: 61,91%. Median age: 59. Cancers: bronchogenic carcinoma: 42,8%, breast carcinoma: 28,5%, ovarian carcinoma: 14,2 %, carcinoma of unknown origin: 9,52%, others: 4,76%. Clinical stages: III B: 57,2%, most of them bronchogenic carcinoma, IV: 42,8%. Total effectiveness: 85,7%. Effectiveness in known origin cancers: 92,1%. Effectiveness in unknown origin cancers: 25%. Pleural effusion recurrence 14,3%. Drugs employed in appropriate drug regimens: cisplatin, carboplatin, etoposide, gemcitabine, vinorelbine, cyclophosphamide, doxorubicin, docetaxel, capecitabine. Conclusions: Systemic chemotherapy after draining effusions is a good approach for treating chemosensitive cancer pleural effusions, because can produce pleurodesis, is etiologic, has a high effectiveness and can improve survival. No significant financial relationships to disclose.