Objective: To describe the epidemiological, clinical and therapeutic characteristics of women under 40 years followed for breast cancer. Method: This is a retrospective and cohort study with descriptive purpose conducted over 10 years on the management of breast cancer in 105 patients under 40 years in the Gynecology Service of the University and Hospital Center of Treichville. Results: The incidence of breast cancer in women under 40 years was 8.4%, and the majority of patients were over 35 years old (64.8%) and had a low socioeconomic level (61.7%). Some patients had classic risk factors for breast cancer: menarche before 12 years (48.6%), nulliparity (20%), family history of breast cancer (1.9%). The discovery of a breast abnormality was made by patients in 97.1% of the cases. Cancers were either isolated (92.4%) or associated with pregnancy (5.7%) or bilateral (1.9%). The majority of cancers were infiltrating ductal carcinomas (86.7%), of SBR II grade (69%). Patients generally benefited from a mastectomy with axillary dissection, framed by chemotherapy. The global survival at 10 years was 5%. Conclusion: This study allowed us to confirm that breast cancers in younger women were a reality in our country and posed us enormous difficulties in their management.