Translation of recommendations on skin cancer prevention formulated by many national and international institutions into efficient steps requires measuring the potential impact in terms of preventable cases. This study analyses the proportion of skin cancers attributable to sun exposure in Turin, Trento and Ragusa. Estimates have been reached by applying the risk models calculated from the case-control study on melanoma in Turin and the Helios multi-centric study on skin carcinomas. The proportion of cases attributable to sun exposure has been subsequently calculated by correcting for the different proportion of skin characteristics among the populations taken into consideration. Attributable risks so calculated show medium to high values for melanoma in Turin (38%) and Trento (29%), while values are lower in Ragusa (17%). As for basal-cell carcinoma, attributable risk values are slightly inferior to those of melanoma. The risk of squamous-cell carcinoma attributable to sun exposure during outdoor work is the highest in Ragusa, with a value of 25%. Taking an annual incidence rate for melanoma of 9 cases per 100,000 inhabitants, and a preventive intervention with 50% of effectiveness, preventable cases should be 2 cases per 100,000 each year. This figure compared with 8 preventable cases of cervix cancer, in a similar population suggests an extremely cautious attitude in taking on programmes aiming to change life styles.