Introduction Breast cancer is the most common cancer in women worldwide. It was estimated that 636 000 incidents cases occurred in developed countries and 514 000 in developing countries during 2002. Breast cancer is also the most important cause of neoplasic deaths among women; the estimated number of deaths in 2002 was 410 000 worldwide. Our study aimed for adjusting breast cancer incidence trends over the longest period available 1987–2007 in Setif for the effect of age and period of diagnosis.

Material and Method Incidence datas were collected in the period 1987–2007 from the population-based cancer registry of Setif, the software used is the Can Reg 4.

Results Breast cancer ranked first among female population. Incidence was highest among women 30-55 age group (63%), the median age at diagnosis was 54–59 age group.

Conclusion It is the most common cancer it represents 21, 1% of all cancer sites reported in Setif cancer registry, more than 50% of new cases are the young women whose age is inferior at 40 years. It represents the first cause of mortality at women in Algeria it accounts 7000 deaths each year. The results suggest that the early detection should become a priority in Algeria.