SUMMARY. Pulmonary Langerhans granulomatosis is a rare disease. This study aimed at presenting the clinical and laboratory data of 11 Greek patients, with a review of the literature concerning the pathogenesis, clinical course, diagnosis and prognosis of this disease. The age of our patients ranged from 18 to79 years with almost all of them being active smokers. The main symptoms at the time of diagnosis were cough and dyspnoea on exertion, while in 3 patients extrapulmonary manifestations of the disease were detected. Radiological findings were indicative of the disease in 7 patients and pulmonary function tests were abnormal in most patients. Diagnosis was made by open lung biopsy in one case, thoracoscopic biopsy in 3 cases, detection of the characteristic immunological markers in bronchoalveolar lavage in 6 cases and characteristic radiological findings in one case. All the patients were advised to stop smoking and no other therapeutic interventions were carried out. Follow-up data were available in 7 patients. Pneumon 2007; 20(1):73-82.