Vertebral body marrow (VBM) from adult donors is currently being used in clinical trials designed to induce a state of donor specific tolerance in recipients of solid organs and/or islet allografts. Adult VBM has been analysed with regards to progenitor cell content; however, since the availability of pediatric donors is limited, marrow from this source has not been well characterized. We have compared isolations from pediatric donors (3 days to 10 years of age) with adult VBM. The cell yield per gram of vertebral body (VB) weight was 1.92x10 8 for adult donors (n=21), 2.94x10 8 in donors <1 year of age (n=4), 2.61x10 8 in donors 1-3 years old (n=8) and 2.35x10 8 in donors 4-10 years of age (n=7), respectively. No significant differences were found between groups. Colony forming capacity, as an index of marrow quality, was also evaluated. CFU-GM, BFU-E+CFU-E and CFU-GEMM were not significantly different in any of the pediatric groups compared with adult marrow. Cell subpopulations were assessed via flow cytometric analysis with CD2, CD3, CD4, CD8, CD19, CD33, CD34, CD45, CD56 and HLA-DR specific monoclonal antibodies. Phenotypic analysis revealed a higher percentage of CD34+ cells in pediatric VBM as compared to adult donors, with a mean of 4.5% (n=10) and 3.4% (n=10) for pediatric and adult donors, respectively. Interestingly, VBM from a 3 day old donor contained 6.6% CD34 positive cells. We conclude that pediatric donors are a suitable source of marrow for use in tolerance induction protocols.