The records of 125 patients treated for superior vena cava syndrome secondary to malignant disease were reviewed retrospectively. The mean age of patients was 55 years. Bronchogenic carcinoma was the cause of the syndrome in 79% of cases, malignant lymphoma 18%, and other tumors 6%. Approximately 80% of the patients obtained good to excellent symptomatic relief. High initial dose radiation therapy (300-400 cGy daily for three fractions) yielded good symptomatic relief in less than 2 weeks in 70% of patients; conventional dose radiation therapy (200 cGy daily, five weekly fractions) yielded the same response in 56% of patients (p = 0.09). Lymphoma patients displayed a 1 year survival of 41%, small cell carcinoma 24%, and other types of bronchogenic carcinoma 17%. Combination of radiation and chemotherapy did not improve response rate, degree of symptomatic relief or long-term survival. Patients exhibiting symptomatic relief within 30 days had a significantly better survival rate than those who did not (p = 0.002). Thirteen percent of patients showed a recurrence of superior vena cava syndrome. There was no correlation between tumor regression and symptomatic relief. Side effects of therapy were minimal; dysphagia was the most common complaint (26% of patients).