We studied a retrospective series of 25 sub-pleural fibromas (benign localized pleural mesotheliomas) of which 23 where excised, collected over a period of 20 years. The current series confirms the excellent prognostic of these rare tumors. They are sometimes bulky, but not infiltrating and discovered by systematic chest X-ray. Modern imaging using CT-Scan and nuclear magnetic resonance can suggest their diagnostic which is confirmed by histopathologic analysis of the usually pediculate and easily removed tumor. Transthoracic needle aspiration is generally of little help for diagnosis. The histopathologic diversity of the tumor is rather confusing but characteristic features can be found with fusiform cells ans collagen stroma. Immuno-histochemistry is more helpful for diagnosis and histogenesis recognition than electron microscopy.