Diagnosis of pulmonary Kaposi's sarcoma can be difficult. Clinical findings and chest X-rays are non-specific and endobronchial diagnostic in about 50% of cases. Additional concomitant infectious complications are frequent. Symptomatic pulmonary Kaposi's sarcoma most oftenly is progressive and has a poor prognosis. Preliminary data suggest effective palliation with radio- and chemotherapy and an improved survival time in selected cases. We present six cases of proven pulmonary Kaposi's sarcoma and discuss clinical course and diagnostic difficulties. Based on this view we propose a diagnostic approach to warrant therapeutic success.