Background Due to the devastating late effects associated with cranial irradiation in young children with CNS tumors, treatment for these patients has evolved to include the use of intensive chemotherapy to either avoid or postpone irradiation. While survival outcomes have improved, late effects data in survivors treated on such regimens are needed. Objective This multi-institutional study comprehensively describes late effects in survivors treated on the Head Start I/II protocols. Methods Survivors of CNS tumors treated on Head Start I/II protocols were enrolled. Late effects data were collected using a validated parent-report questionnaire. Social, emotional, and behavioral functioning and quality of life were assessed using parent-report on the BASC-2 and CHQ-PF50 questionnaires. Results Twenty one survivors (medulloblastoma=13, sPNET=4, ATRT=1, ependymoma=3) were enrolled. Ten (48%) were irradiation-free. Late effects (frequency; median time of onset since diagnosis) included ≥ grade III hearing loss (67%; 3.9 years), vision (67%; 4.1 years), hypothyroidism (33%; 4 years), growth hormone (GH) deficiency (48%; 4.7 years) and dental (52%; 7.1 years) and no cases of secondary leukemia. Irradiation-free (versus irradiated) survivors reported low rates of hypothyroidism (0/10 vs 7/11; p=0.004) and GH deficiency (2/10 vs 8/11; p=0.03). The BASC-2 and CHQPF-50 mean composite scores were within average ranges relative to healthy comparison norms. Neither age at diagnosis nor irradiation were associated with these scores. Conclusions Irradiation-free Head Start survivors have lower risk of hypothyroidism and GH deficiency. Secondary leukemias are not reported. With extended follow up, survivors demonstrate quality of life, social, emotional, and behavioral functioning within average ranges.