The authors report 4 cases of patients with benign fibrous mesothelioma of the pleura, an extremely rare pathology (not more than 500 cases reported to date in the literature), and discuss biological behaviour, diagnosis and surgical treatment. Benign fibrous mesothelioma is generally diagnosed by chance during chest x-ray given that it is paucisymptomatic; diagnostic procedures include thoracic CT (which may be supplemented by transthoracic needle biopsy) and bronchoscopy. Treatment is surgical and consists of exeresis of the neoplasia; prognosis is excellent and cases are reported in the literature of 24-year follow-up without recurrence. Lastly, the authors underline the importance of modern immunohistochemical techniques which help the surgeon to formulate a precise diagnosis and to differentiate benign fibrous mesothelioma.