BackgroundTaiwan’s National Health Insurance has covered targeted therapy, namely cetuximab, for locally advanced head and neck cancers (LAHNC) since July 2009. This study examines treatment trends and survival effects of locally advanced head and neck cancer patients before and after Taiwan’s National Health Insurance covered cetuximab.MethodsWe examined treatment trends and survival effects for patients with LAHNC using Taiwan’s National Health Insurance Research Database. Patients who received treatment within 6 months were categorized as either nontargeted or targeted therapy groups. We analyzed treatment trends with the Cochran-Armitage trend test and explored factors associated with treatment selection and survival effects using multivariable logistic regression and Cox proportional hazards models.ResultsOf the 20,900 LAHNC patients included in the study, 19,696 received nontargeted therapy, while 1,204 received targeted therapy. Older patients with more comorbid conditions, advanced stages and patients with hypopharynx and oropharynx cancers were more likely to receive targeted therapy with concomitant cetuximab treatment. Patients who received targeted therapy in addition to other treatment modalities had a greater risk of one-year and long-term all-cause mortality or cancer-specific mortality than those without receiving targeted therapy (P < 0.001).ConclusionsOur study found an increasing trend in cetuximab utilization among LAHNC after reimbursement in Taiwan, but overall usage rates were low. LAHNC patients receiving cetuximab with other treatments had higher mortality risk than those receiving cisplatin, suggesting cisplatin may be preferred. Further research is needed to identify subgroups that could benefit from concomitant cetuximab treatment.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12885-023-11061-4.