The incidence of breast cancer in the city of Palermo and its Province was investigated. The cancer rate was higher in the city of Palermo (100.8/100,000/year), a great southern urban area, than in the 81 municipalities of the Province (79.2/100,000/year). Rates were also compared with those in other geographic areas of Italy, showing a smaller than expected negative north-south gradient in incidence, especially in the young age group, as shown by the cumulative risk observed in the 0-54-year-old group. These findings confirm the role of recent life style changes in the cancer risk distribution.