To determine the extent of research waste in the field of nasopharyngeal carcinoma (NPC).In this cross-sectional study, we explored the rates, causes and predictors of discontinuation and nonpublication of NPC clinical trials. The sample was derived using the ClinicalTrials.gov advanced search function. Adjusted logistic regression was used to ascertain the effect of trial characteristics on completion and publication status. If a trial discontinuation explanation or publication status could not be determined through the systematic search, the corresponding author was emailed.Ultimately, 311 NPC clinical trials were included (255 [82.0 %] completed and 56 [18.0 %] discontinued trials). The most common reason for trial discontinuation was poor accrual (50 %, 23/46). Industry funding (adjusted OR, 3.12; P = 0.003) and recurrent/metastatic setting (adjusted OR, 11.95; P = 0.003) were significantly associated with increased likelihood of trial discontinuation. Of the 207 completed trials included in the publication query, 141 (68.1 %) were published in peer-reviewed journals, 10 (4.8 %) had results only available on ClinicalTrials.gov, and 56 (27.1 %) remained unpublished 3 or more years after trial completion. Radiation with or without pharmacologic interventions significantly increased the potential of publication (adjusted OR, 3.20; P = 0.048). Among published trials, the median time to publication was 28.47 months (interquartile range, 15.27-44.98 months).We identified the difficulties inherent in NPC clinical trials from completion to publication. This represents considerable research waste in NPC, thus raising ethical concerns about the concealment of clinical data and futile patient participation and attendant risks.Copyright © 2023 Elsevier Ltd. All rights reserved.