Transgenic mice homogeneously expressing enhanced green fluorescence protein (EGFP) in primitive hematopoietic cells and all blood cell progeny, including erythrocytes and platelets, have not been reported. Given previous data indicating H2K^b promoter activity in murine hematopoietic stem cells (HSCs), bone marrow (BM), and lymphocytes, an H2K^b enhancer/promoter EGFP construct was used to generate transgenic mice. These mice demonstrated pancellular EGFP expression in both primitive BM Sca‐1⁺Lin⁻Kit⁺ cells and side population (SP) cells. Additionally, all peripheral blood leukocytes subsets, erythrocytes, and platelets uniformly expressed EGFP strongly. Competitive BM transplantation assays established that transgenic H2K^b‐EGFP HSCs had activity equivalent to wildtype HSCs in their ability to reconstitute hematopoiesis in lethally irradiated mice. In addition, immunohistochemistry revealed EGFP transgene expression in all tissues examined. This transgenic strain should be a useful reagent for both murine hematopoiesis studies and functional studies of specific cell types from particular tissues. genesis 42:17–22, 2005. © 2005 Wiley‐Liss, Inc.