Flow cytometry is a powerful technology that allows not only multiparameter quantitative data analysis at single cell resolution but also simultaneous cell separation of different populations of interest at high speed. It has been rapidly employed in biological research and clinical diagnostics. This technology has enabled the thorough understanding of murine hematopoiesis, especially the physiology of surface marker-defined hematopoietic stem and progenitor cell populations. The isolation of these populations has been well established over the last three decades with a large consensus among leading laboratories. Here, we describe a detailed methodology protocol of two different state-of-the-art approaches to isolate bone marrow cells and purify hematopoietic stem and progenitor cells via flow cytometry. Different gating schemes are introduced to identify well-defined populations of murine hematopoietic stem and multipotent progenitor cells.