Breast cancer is the first cancer of women in the world. With nearly 1.7 million new cases diagnosed each year around the world, breast cancer is the most common cancer in women and the major public health problem. In Morocco, its incidence continues to increase. Its occurrence is a dramatic event in a woman's life, it is still unhappy and difficult to accept when it is a young woman. This is a retrospective study of 93 patients under 35 years of age with breast cancer who were recruited to the Gynecology and Obstetrics II Department of Hassan II University Hospital in Fez, Morocco, over a period of 5 years. The purpose of the study was an analysis of clinical, therapeutic, evolutionary and prognostic data for breast cancer in women aged 35 and under. The prognosis of breast cancer in our young patients is unfavorable, seems to be related to an advanced stage of the disease, but also a particular biological profile, as well as the data of the literature.