Summary Malignant breast cancer is the most common neoplasm in women in most developed countries. The majority of cases of breast cancer are probably connected with environmental factors and lifestyle. According to the current state of knowledge, modification of risk factors may contribute to the reduction of breast cancer cases and individual assessment performed by selecting a group of women with increased risk may help to reduce mortality. The purpose of the study was to analyze risk factors affecting the increase of odds ratio (OR) for developing breast cancer and to define in which range OR increases or decreases significantly. The participants of the study were healthy women with no changes in mammary glands and women with breast cancer diagnosed on the basis of histopathological examination. The study was carried out in Great Poland and Lubuskie province between 2005 and 2006. The total number of participants was 371 females, aged 35-70 years. The highest risk of breast cancer was observed in women over 55, BMI >30, who had >5 deliveries, with cancer family history and suffering from severe depression. Apart from cancer family history all other factors are potentially modifiable. Appropriate education of women can result in reduction of breast cancer risk.