Symptomatic malignant pleural effusions are common sequelae in patients with certain malignancies. Pleurodesis via bedside thoracostomy is the current treatment option most commonly used. To our knowledge, this is the first prospective randomized trial to examine which agent, bleomycin or talc slurry, is superior in terms of effectiveness, safety, and cost.Between July 1992 and March 1995, 35 patients presenting to our medical center with symptomatic malignant pleural effusions were prospectively randomized to undergo chemical pleurodesis with either bleomycin or talc slurry via bedside thoracostomy. The conditions of patients were assessed and graded before and after treatment concerning pain, dyspnea, and chest radiographs.Twenty-nine patients who underwent 33 treatments (14 with bleomycin and 19 with talc) were available for follow-up. Follow-up ranged from 2 weeks to 8 months (mean, 1.7 months). Both groups demonstrated notable improvement in both pain and dyspnea following treatment, but there were no statistically significant differences between groups in the amount of improvement (two-tailed Student's t test). Permanent control of effusions, defined objectively on chest radiograph, was achieved with 11 bleomycin treatments (79%) and 17 talc treatments (90%) (p=0.388). The procedures were well tolerated and no significant adverse effects were observed. Talc is a much less costly agent than bleomycin ($12.36 cost to our medical center per treatment for talc vs $955.83 for bleomycin).Given the similar efficacy and significant cost advantage, we conclude that talc is the agent of choice when utilizing pleurodesis for control of symptomatic malignant pleural effusions.