This review evaluates the role of the tumor microenvironment of breast cancer focusing on the evidence showing that tumor-associated macrophages, neutrophils, and mast cells directly participate in tumor initiation, proliferation, and metastasizing. This study also describes microenvironment cells pathologic assessment relevant for prognostication and treatment decision. Tumor-associated macrophages stimulate breast tumor progression, including tumor cell growth, invasion and metastasizing. Tumor-associated neutrophils are more prevalent in patients with severe disease or resistance to treatment and it can be explained by their pro-tumor / immunosuppressive characteristics. The contribution of mast cells to tumor development and progression appears to be a controversial area of research. The ability of mast cells to promote angiogenesis is viewed as a key process in promoting tumor development. However, elevated level of mast cells at tumor sites seems to be connected with improved outcomes.