Borgström B, Fridström M, Gustafsson B, et al. - Researchers conducted this prospective longitudinal study to analyze the long‐term outcomes of prepubertal and pubertal boys undergoing testicular biopsy for fertility preservation (FP). Between 2003 and 2010, 21 boys (aged 1.5‐14.5 years) who had a testicular biopsy for FP prior to allogeneic (n = 20) or autologous (n = 1) hematological stem cell transplantation were examined. Pubertal boys were encouraged to produce a sperm sample through masturbation during counseling, whereas prepubertal boys were presented with surgical testicular tissue retrieval as an alternative for experimental FP. Twenty boys [14 in prepuberty and six in early puberty (Tanner stage 2‐3)] had open testicular biopsies. During continuous clinical follow‐up, no long‐term risks were reported. Experimental testicular biopsies for FP have been well accepted by patients and families, despite the lack of methods for the use of prepubertal tissue for fertility treatment.