Objective The National Comprehensive Cancer Network (NCCN) has established guidelines for treating epithelial ovarian cancer (EOC) which includes cytoreductive surgery and platinum and taxane-based chemotherapy (CT). The objective of this study was to determine the reasons for failure to deliver NCCN-adherent care at an NCCN cancer center serving a diverse racial and socioeconomic population. Methods Medical records of women with EOC diagnosed between 2004 and 2009 were reviewed for demographic, clinical, tumor, treatment, and survival data. Independent reviewers determined if their treatment met criteria for being NCCN-adherent. Progression-free survival (PFS) and overall survival (OS) were calculated with Kaplan-Meier estimates and compared with the log-rank test. Results 367 patients were identified. 79 (21.5%) did not receive NCCN-adherent care. Non-adherent CT in 75 patients was the most common reason for failure to receive NCCN-adherent care. 39 patients did not complete CT due to treatment toxicities or disease progression. 12 patients received single agent CT only and 4 received no CT due to comorbidities. 2 patients declined CT. 18 patients died in the postoperative period without receiving CT. 8 patients did not undergo cytoreduction due to disease progression or comorbidities. PFS and OS were improved in the NCCN-adherent cohort (PFS: 5.7 vs. 18.3 months, p <.005) (OS: 11.4 vs. 49.5 months, p <.005). Conclusions The vast majority of patients at an NCCN cancer center received NCCN-adherent treatment. Reasons for failure to receive NCCN-adherent care were variable, but most did not receive chemotherapy in accordance with guidelines due to comorbidities or disease progression. © 2014 Elsevier Inc.