Family psychosocial risk screening is an important initial step in delivering evidence-based care in hematopoietic stem cell transplantation (HCT). Establishing an evidence-based screening approach that is acceptable, reliable, and valid is an essential step in psychosocial care delivery. This is a 3-institution multimethod study. In part 1, caregivers of children about to undergo HCT (n = 140) completed the Psychosocial Assessment Tool-Hematopoietic Cell Transplantation (PAT-HCT), a brief parent report screener adapted for HCT, and validating questionnaires.