Background: To determine the impact of chemotherapy on survival of patients with stage I ovarian immature teratomas. Methods: Data obtained from the National Cancer Database from 2004-2013. Kaplan-Meier methods and multivariate Cox regression models were used for statistical analyses. Results: Of 888 patients (median age 24 years), 76%, 7%, 15%, 3% were stages I, II, III, and IV, respectively. 27%, 28%, 38%, and 8% had grades 1, 2, 3 and 4. The predominant racial group was White (50%) and remainder Black (19%), Hispanic (16%), Asian (6%) and other (9%). 64% had fertility sparing surgery and 55% received chemotherapy. For all patients, 5 year survival was over 90%. Chemotherapy did not change the 5 year survival for stage I or stage II disease (p = 0.35 and p = 0.69, respectively). However, chemotherapy improved 5 year survival from 59% to 76% in stages III-IV (p < 0.01). When controlling for other factors, older age (HR 3.2, p < 0.01), stages II and III-IV (HR 6.0, p < 0.01; HR 10.6, p < 0.01) and grades 3-4 (HR 15.3, p < 0.01) had worse survival. In a subset analysis of stage I patients chemotherapy did not improve 5 year survival of those with stage I grade 1 (p = 0.75) but chemotherapy did improved the survival of those with stage I grade 2 disease from 85% to 99% (p = 0.04). Conclusions: The overall survival of patients with immature teratomas is excellent. In patients with stage I grade 2 or higher disease chemotherapy was associated with an improved overall survival.