Abstract. Breast cancer in young female patients represents a public health problem in developing countries. The objectives of the study were to study the epidemiological and histological characteristics of breast cancer in female patients under 35 years of age. This was a retrospective analytical study of a series of 158 cases of breast cancer in female patients under 35 years of age, conducted at the University Teaching Hospital of Lomé between 2000 and 2015. A total of 158 cases were collected, representing 36.2% (436) of all breast cancer cases. The average age of the patients was 30.9 years (range, 16-35 years). A family history of breast cancer at the 1st or 2nd degree was identified in 13.9% of cases. Genetic mutation studies were carried out for 7 patients, 5 of which revealed mutations (4 BRCA1 and 1 BRCA2). According to the locus, the cancer was located preferentially in the left breast in 88 cases (55.7%). Malignant mammary lesions were epithelial tumors (n=144 cases, 91.1%), infiltrating (n=125 cases, 79.1%) and non-infiltrating (n=19 cases, 12.0%). The other histological groups consisted of 8 cases of sarcomas (5 cases of angiosarcoma, 2 cases of fibrosarcoma and 1 case of Kaposi's sarcoma), 5 cases of lymphomas and one case of melanoma. Not otherwise specified infiltrating ductal carcinomas were SBR II and III in 43.2 and 35.2% of cases, respectively. The tumors classified as T4 were the most frequent (30.4%). Regarding the lymph node status, lymph node metastasis was noted in 22.8% of cases. Studies of hormone receptors were carried out in 23 patients and were positive for 11 patients: Estrogen receptor (ER)+plus progesterone receptor (PR)+(7 patients), ER+PR-(4 patients). Of the aforementioned 8 cases of sarcoma, 5 were angiosarcoma. The lymphomas were predominantly Burkitt's type for 4 cases. Mammary ultrasonography was performed in 45.6% of the patients and 54.4% underwent the combined ultrasonography and mammography. Ultrasound identified one or more sign of malignancy in 67 patients (42.4%), and combined ultrasonography and mammography classified 51.9% of lesions in BIRADS 4 and 5. The incidence of breast cancer in young Togolese patients is high. It is a disease distinguished by a delay in diagnosis, which contributes to the high number of cases that initially diagnosed at an advanced stage, particularly the high histo-prognosis grades of infiltrating ductal carcinoma. These results indicate a genetic origin; therefore, a thorough investigation into genetic mutations should be carried. In addition, further collaborative studies are required to verify these results.