Patient-reported outcome measures (PROMs) are questionnaires completed by patients or caregivers without influence by health care professionals. As such, PROMs show subjective health experiences, enhance the clinical information available to providers, and inform clinical action. The objective of this systematic review is to identify and list which validated PROMs have been used to monitor health-related quality of life in pediatric patients with nonmalignant hematology (hemophilia, immune thrombocytopenia, sickle cell disease, and thalassemia). Databases (MEDLINE, Embase, HaPI, CINAHL, and PsycTESTS) were searched to identify publications that validated or used PROMs as an outcome measure in the 4 disease groups. Overall, 209 articles met the inclusion criteria, identifying 113 PROMs. Of the 113 identified PROMs, 95 are generic and can be used in multiple disease groups. The Pediatric Quality of Life Generic Core Scales was the most frequently used generic PROM (68 studies). The 18 remaining PROMs were disease specific. The results of this review, together with the COSMIN tool for selecting outcome measures, will allow clinicians to evaluate the PROMs that are best suited to their patient population. In addition, the focus groups are currently being conducted with patients, parents, and clinicians to determine the optimal use of PROMs in the clinical environment.