We report our experience in the treatment of pleural effusion in 25 patients with metastatic breast cancer. Seventeen patients received initial systemic therapy and in 13 of them local intrapleural therapy was subsequently employed; the remaining 8 patients received local therapy only. Several modalities of local treatment were used: intrapleural chemotherapy with thiotepa and 5-fluorouracil; the production of pleural adhesion by the use of chest drainage alone or associated with instillation of sclerosing agents, such as nitrogen mustard or tetracycline. Of the 21 patients who were subjected to local therapy, 19 (90.5%) achieved an objective response (16 complete (76.2%) and 3 (14.34%) partial). Complete responses were observed exclusively in patients who had pleurodesis. Our data suggest that pleurodesis is the treatment of choice for neoplastic pleural effusion and that the use of tetracycline as a sclerosing agent is the most useful because of its availability, low cost and low morbidity.