Background and objective: In recent years, the tumor microenvironment has become increasingly recognized as an influential factor in breast cancer development and growth. The parameters that form the microenvironment are the tumor stroma ratio and tumor infiltrating lymphocytes. In addition, tumor budding, which shows the ability of the tumor to metastasize, gives information about the progression of the tumor. In this study, the combined microenvironment score (CMS) was determined with these parameters, and the relationship between CMS and prognostic parameters and survival was evaluated.Materials and methods: In our study, tumor stroma ratio, tumor infiltrating lymphocytes, and tumor budding were evaluated in hematoxylin-eosin sections of 419 patients with invasive ductal carcinoma. Patients were scored separately for each of these parameters, and these scores were summed to determine the CMS. The patients were divided into 3 groups according to CMS and the relationship between CMS and prognostic parameters and the survival of the patients was studied.Results: The patients with CMS 3 had higher histological grade and Ki67 proliferation index compared to CMS and 2. Additionally, lymphovascular invasion, axillary lymph node and distant metastasis were more common. Disease-free, and overall survival were significantly shortened in the CMS 3 group. CMS was found as an in-dependent risk factor for DFS (HR: 2.144 (95 % CI: 1.219-3.77) p: 0.008), but not an independent risk factor for OS.Conclusion: CMS is a prognostic parameter that can be easily evaluated and does not require extra time and cost. Evaluating the morphological parameters of the microenvironment with a single scoring system will contribute to routine pathology practice and predict patient prognosis.