The aim of this study was to evaluate the incidence of malignant breast tumors in the Province of Sassari, Sardinia (Italy) in the period 1992-2002 and to report the variations in comparison to the 1974-1985 period. The analysis of our data showed that the overall number of malignant breast tumors was more than doubled from 1,139 cases in the period 1974-1985 to the 2,735 cases in the period 1992-2002, and the mean rate/100,000 changed from 43.4 to 106.0. The incidence in the age classes 45-64 years, which were at enhanced risk for breast cancer, was globally increased, changing from 143.6/100,000 to 198.7/100,000. On the other hand, the incidence in the youngest age classes (30-34 yrs) was reduced from 59.5% to 27.0%. The analysis of the histotypes showed a relative reduction of ductal carcinoma in the period 1992-2002 in comparison to the previous period 1974-1985 (65.2% vs 82.0%) whereas the incidence of anaplastic forms increased in advanced ages of life. We reported an important reduction of T0 tumors from 3.4% to 0.1%. These data could be due to the low diffusion of screening programs in Sardinia. Tumor metastases were more frequent in advanced age classes. In conclusion, the worrying data of the strong reduction of T0 cases, the increased age of first diagnosis and the advanced forms with positive nodal metastases showed that the prevention program has not been yet well organized.