Poverty is correlated with negative health outcomes in pediatric primary care and subspecialties; its association with childhood hematopoietic stem cell transplantation (HSCT) patterns of care and clinical outcomes is not known. We describe family-reported financial hardship at a primary referral center in New England and explore the relationship between measures of poverty and patterns of care and clinical outcomes. Forty-five English-speaking parents of children after allogeneic HSCT in the prior 12 months completed a 1-time survey (response rate 88%). Low-income families, defined as ≤200% federal poverty level (FPL), were compared with all others. Eighteen (40%) families reported pre-HSCT incomes ≤200% FPL. Material hardship, including food, housing, or energy insecurity was reported by 17 (38%) families in the cohort. Low-income families reported disproportionate transplantation-related income losses, with 7 (39%) reporting annual income losses of >40% compared with 2 (18%) wealthier families (P = .02). In univariate analyses, 11 (61%) low-income children experienced graft-versus-host disease (GVHD) of any grade in the first 180 days after HSCT compared with 2 (7%) wealthier children (P = .004). We conclude that low income and, in particular, material hardship, are prevalent in a New England pediatric HSCT population and represent targets for improvement in quality of life. The role of poverty in mediating GVHD deserves further investigation in larger studies that can control for known risk factors and may provide a targetable source of transplantation-associated morbidity.