OBJECTIVE Human chorionic gonadotropin (HCG)-secreting germ cell tumors (GCTs) are rare childhood malignancies with unique clinical manifestations but delayed diagnosis is common. The purpose of this study is to investigate the clinical manifestations and endocrine dysfunction of Taiwanese children with HCG-secreting GCTs. METHODS From 1991 to 2011, 24 children (19 boys and five girls) with HCG-secreting GCTs were evaluated for their clinical findings and endocrine functions. RESULTS The mean age at diagnosis of the study patients was 10.8 ± 3.1 years. Of the 24 patients, 20 had central nervous system (CNS) GCTs and four had primary mediastinal GCTs (PMGCTs). The most common pathologic findings were germinomas and mixed type GCTs. The common initial symptoms and signs included polyuria, polydipsia, rapid growth, neurologic deficit,sexual precocity, and growth retardation. There was a delay in diagnosis in about 60% of patients. Diabetes insipidus and hypopituitarism were common endocrine dysfunctions in patients with CNSGCTs. Twelve boys had gonadotropin-independent puberty upon diagnosis, which were related to their high serum β-hCG levels. None of the five girls had this disorder despite their high serum β-hCG levels. Three of the four PMGCTs patients had the classic form of Klinefelter syndrome. CONCLUSIONS Taiwanese children with HCG-secreting GCTs often have clinical manifestations related to endocrine dysfunction. High index of suspicion is important to avoid delayed diagnosis in these children.