• Purpose Endocrine complications and semen abnormalities such as oligo/azospermia are common complications which can affect quality of life. But prevalences in Korea are rarely known. Thus, we investigated the prevalences of endocrine complications and semen abnormalities in childhood cancer survivors. We also purposed to evaluate their quality of life. • Method We performed physical examination and fasting blood test (fasting glucose/insulin, lipid) about metabolic syndrome. We also checked sex hormone level (LH/FSH/estradiol or testosterone). Anti-mullerian hormone level was checked in females to evaluate ovarian reserve. Semen analysis was performed in males. We also conducted a survey about quality of life. • Results Subjects were 54 childhood cancer survivors. The mean age of patients was 20.0±3.1 years. Thirty-three (61.1%) were age ≥19 years and 22 (40.7%) were males. Primary tumor were leukemia/lymphoma in 25 patients (46.3%), brain tumor in 7 (13%), and solid tumor in 22 (40.7%). Nineteen (35.2%) received radiation therapy: 8 with cranial irradiation, 3 with total body irradiation. Nine (16.7%) received peripheral blood stem cell transplantation ( PBSCT): 5 with allogeneic PBSCT and 4 with autologous PBSCT. Among all 54 patients, 8 (14.8%) were obese and 9 had dislipidemia. Vitamin D deficiency was present in 41 patients (75.9%). Nineteen adults (61.3%) and 4 adolescents (22.2%) showed decreased bone density (BMD z-score-1). Ovarian failure was suspected (AMH0.08 ng/mL) in eight (25%) females. Seventeen males performed semen analysis, and eight among them (47.1%) showed azo/oligospermia. Percent of patients who had depressive mood was higher than normal population (27.7 vs. 13.6%). None of the patients were current smoker, and percent of alcohol drinking was lower than normal population (50 vs. 91.6 %). • Conclusion Endocrine complications such as metabolic syndrome, osteopenia and gonadal dysfunction were common in childhood cancer survivors. Prevalence of depression seems to be higher than normal population. Therefore, comprehensive long term follow up care for childhood cancer survivors based on risk factors is indispensible. Furthermore, proper primary and secondary interventional strategies for possible late effects should be developed.