Although breast cancer and endometrial cancer are two frequent female cancers, finding synchronous primary cancers in the same patient is a comparatively uncommon occurrence. We present the case of a Libyan woman who developed synchronous breast cancer, endometrial cancer, and small lymphocytic lymphoma. For the previous six months, a 49-year-old female patient had a right breast mass. An ultrasound scan revealed an uneven doubtful growth in the right breast as well as swollen of the axillary lymph nodes. After a wide local excision, histopathology revealed that the patient had invasive ductal carcinoma of the breast with a positive resection margin, and he was admitted to the Surgery Department. No distal metastasis was seen on a computed tomography (CT) scan of the chest, abdomen, or pelvis, so the patient had a right mastectomy and axillary clearance. Residual invasive ductal carcinoma was found on histopathology and immunohistochemistry with positivity for the estrogen receptor and the progesterone receptor. Small lymphocytic lymphoma (SLL) affected the axillary lymph nodes, affirmed by immunohistochemical staining positive for CD20, CD5, CD23 and BCL-2 while negative for CD3 and Cyclin D1. Resection margins were free. Second cancers are characterized by being linked to SCL, and some researchers have described that the risk of second cancers is elevated in SCL patients. We represent a combined case of synchronous primary SCL with breast cancer and endometrial cancer in a woman which is a rare occurrence.