Bone marrow-derived stem cells (BMSCs) are a valuable resource for regenerative medicine due to their multipotent properties, including the ability to differentiate into various cell types such as osteoblasts, chondrocytes, and adipocytes. These cells are commonly used in tissue engineering, cell therapy, and studies of hematopoiesis. Isolating BMSCs from mouse bone marrow provides a robust model for in vitro and in vivo experimentation, as well as for exploring stem cell biology and therapeutic applications. This protocol outlines a method for isolating bone marrow stem cells from the femur of mice using a combination of enzymatic digestion and density gradient centrifugation. The process involves several wash and centrifugation steps to separate the mononuclear cell fraction, which contains the majority of the stem cells. The isolated BMSCs can then be cultured for further expansion or differentiation studies. This protocol is designed to yield a purified population of stem cells suitable for downstream applications in research and clinical investigations.