Aim: The aim of this study is to compare the differences in breast cancer therapy, health-care service practices, and their availability in ten European countries—Albania, Bosnia and Herzegovina, Bulgaria, Kosovo, Montenegro, Republic of North Macedonia, Croatia, Romania, Slovenia, and Republic of Serbia. Methods: An inquire survey was conducted among oncologists in the participating countries. The questionnaire was of qualitative character and focused on several key areas as screening practices, diagnosing, treatment, and health-care procedures utilization. The results were processed through comparative and percentage analysis. Results: All of the observed countries have national registries for breast cancer, but only in five, a mechanism of controlled action of early detection is implemented. Ninety percent of the countries have implemented in the national guidelines the European Society of Medical Oncology recommendations, while National Comprehensive Cancer Network is considered in only 50%. In all countries, digital mammography is a universal diagnostic method. Pathohistological analysis, including HER2 receptor expression and determination of the level of progesterone and estrogen receptors, is routinely performed in all countries prior to therapy. Some differences are observed in terms of FISH/CISH methods, determination of Ki-67 volume, and prognostic molecular assays. Trastuzumab is used as neo-adjuvant therapy in HER2-positive disease in all countries, while in Bosnia and Herzegovina and Croatia, only pertuzumab is used. Psychological support is integrated into the professional guidelines for treatment and monitoring in Bosnia and Herzegovina, Bulgaria, and Serbia. Conclusions: The international guidelines should be followed strictly, and some improvements in the health policies should be made in order to decrease the differences and inequalities in the availability of the breast cancer (BC) health services in the Central and Eastern European countries.