INTRODUCTION: Breast cancer is the leading cause of cancer-related death in Mexico, with high mortality associated with spinal bone metastasis. We propose to standardize a murine model of bone metastasis to study and understand the tumor microenvironment. MATERIALS AND METHODS: An experimental, prospective, longitudinal study was conducted using 18 CD1/Nu/Nu 30g nude mice. Two cell lines, MCF-7 and 4T1, were inoculated, clinical follow-up was performed, and biopsy samples were obtained for histopathological evaluation. RESULTS: Histopathological evaluation of models inoculated with the MCF-7 cell line showed no tumor development, while inoculation with the 4T1 cell line resulted in tumor development, as evidenced by PET-CT and histopathology, using 5,000 and 1,000 cells, respectively. CONCLUSIONS: The use of this model is proposed for studying the clinical, molecular, and prognostic aspects of breast cancer progression by inoculating 1,000 cells of the 4T1 cell line.