Homeostasis of the hematopoietic system has its roots in the maintenance of hematopoietic stem cells (HSCs) in the bone marrow (BM). HSCs change both phenotypically and functionally with physiological age. The alterations noted in aged HSCs are thought to be a consequence of both cell-intrinsic and extrinsic changes. We review here the age-related changes that the BM microenvironment exerts on HSCs.