Breast cancer is a malignant tumor that primarily affects women between the ages of 50 and 69. In recent years, a higher incidence of incidence has also been observed in younger women aged 30 and 40. By representation, this is the most common form of cancer in women both in the world and in Croatia. Breast cancer is an important public health problem, which is also indicated by the fact that in Croatia the mortality rate for breast cancer is 15,7 per 100 000 inhabitants for both sexes. Epidemiological studies have shown that there are significant risk factors connected to the tumor, including heredity, age, physical activity, lifestyle and eating habits, reproductive activity, socioeconomic status, hormonal factors etc. Secondary prevention, including mammography and clinical examination, reduces mortality caused by breast cancer. The aim of the paper is to analyze the rates of breast cancer incidence in Primorsko-goranska county (PGŽ) in the period between 2004 and 2013. Over the course of the aforementioned period, 2047 women were affected by breast cancer in PGŽ. The analysis of the overall rate of breast cancer incidence in women in PGŽ for the aforementioned period shows a trend of decline. The age-specific incidence rate was recorded after 45 years of age. In 2013, breast cancer occurs at an earlier age (20-24 years of age) than in 2004. The materials and methods used in the paper are the incidence data for cancer incidence of the Croatian National Institute of Public Health. Population data according to the 2001 and 2011 census of the Central Bureau of Statistics were used.