Despite undoubted success in early diagnosis and treatment of breast cancer, it remains one of the most common and lethal neoplastic diseases in the world among women. Adequate model systems, including cell cultures, can help us better understand breast cancer biology as well as for the discovery of new diagnostic, prognostic and therapeutic strategies. This review summarizes some of the main characteristics of cell cultures (primary cell cultures and immortal cell lines; 2D and 3D cell cultures) used in current biomedical research and their strengths and weaknesses.