Background: Professional guidelines have been developed to promote discussion between providers and newly diagnosed young adults with cancer about the possibility of cancer treatment–related infertility, but previous research suggests many young adults fail to receive this information. The aim of this study was to examine rates of and factors predictive of oncologists' compliance with national guidelines for discussing potential treatment-related infertility with newly diagnosed young adults with cancer seen at an NCI-designated comprehensive cancer center. Methods: We reviewed data from the electronic medical record for new clinic encounters between medical oncologists and young adults with cancer (ages 18–39 years) from 2010 to 2012. Data from oncologist discussions of fertility preservation were abstracted, as were patient (age, sex, race, ethnicity, cancer type) and oncologist (gender, graduation year from fellowship) characteristics. Results: A total of 1,018 cases were reviewed, with 454 patients (mean, 31.5 years; 67.8% women) meeting inclusion criteria. Overall, 83% of patients were informed about potential treatment-related infertility, with patients with breast cancer (85% informed), Hodgkin lymphoma (95% informed), non-Hodgkin's lymphoma (94% informed), leukemia (88% informed), or testicular cancer (100% informed) more likely to be informed than those with other cancer types (60%–74% informed). There was a significant effect for patient sex (odds ratio, 3.57; CI, 1.33, 9.60; P=.012), with women being more likely to be informed than men. Conclusions: Reported compliance with fertility preservation guidelines was greater than published rates. Higher compliance rates in female patients and in patients with cancers more common among young adults may reflect greater awareness of fertility-related concerns among these patients and their providers.