['It is unknown whether receiving treatment that is discordant with practice guidelines is associated with improved survival in patients with nasopharyngeal carcinoma. The objectives of this study were to characterise national treatment patterns, analyse whether treatment outside of practice guidelines is associated with overall survival, and identify variables associated with receiving guidelines-discordant care in the USA.', 'This was a retrospective cohort study of 1741 nasopharyngeal carcinoma patients in the National Cancer Data Base (2003-2006). Treatment regimens were compared with the 2004-2006 National Comprehensive Cancer Network guidelines. Statistical analyses included chi-square, Kaplan-Meier, multivariable logistic, and Cox regression.', 'Nearly 26% of our cohort received care discordant with practice guidelines. In multivariable analysis, patients with stage IVC disease (odds ratio 2.59, 95% confidence interval 1.66-4.04) were more likely to receive guidelines-discordant care when compared with those with stage II-IVB disease. The most common treatment deviation for those with stage I disease was overtreatment with chemoradiation therapy. Receiving guidelines-discordant care was associated with an increased risk of death (hazard ratio 1.46, 95% confidence interval 1.25-1.69).'] Is receipt of Care Discordant with Practice Guidelines Associated with Compromised Overall Survival in Nasopharyngeal Carcinoma?