While an elevated risk of second malignant neoplasms (SMNs) has been observed in men treated for germ cell tumors (GCTs), risk of SMNs have not been quantified in adult women nor in girls treated for GCTs. One-year survivors of primary GCTs diagnosed between January 1980 and December 2012 were identified from Surveillance, Epidemiology, and End Results registries (SEER 9). Risk of SMNs were calculated using SEER*Stat. Among 1,507 patients, a total of 47 SMNs were identified.