The particular point of view, recently published by Gerolamo Chiappino, on the pathogenetic role of asbestos fibres size in the origin of mesothelioma and on the possibility of mesothelioma prevention until the middle of the '80s needs to be critically clarified. The suggestion of an exclusive role of ultrashort and ultrathin fibres in the origin of mesothelioma is based on a biased interpretation of the literature. A review of the epidemiological, experimental, and molecular literature suggests that Chiappino's statements on the role of dose, dose-response effect, and genetic susceptibility are scientifically unsound Chiappino states that, in the past, in the workplaces where use and exposure to asbestos were not stopped, any reduction in the intensity of exposure by means of dust control measures or personal protective equipment would not have contributed to reduce the frequency of mesothelioma. In the authors' opinion the underlying assumptions are invalid.