ABSTRACT Background Epilepsy is a neurological disorder characterized by recurrent seizures. We aimed to investigate the association between the percentage of dietary carbohydrate intake (DCI) and epilepsy prevalence among American adults. Methods We analyzed the data from 9,584 adults aged 20–80 years who participated in the National Health and Nutrition Examination Survey from 2013 to 2018. Logistic regression was applied to explore the association between the percentage of DCI and epilepsy prevalence. Results A total of 146 (1.5%) individuals with epilepsy were enrolled in this study. The average age of the participants was 56.4 years, and 5,454 (56.9%) individuals were female. A high DCI was associated with an increased prevalence of epilepsy (odds ratio [OR], 4.56; 95% confidence interval [CI], 1.11–18.69; P = 0.035) after adjusting for age, sex, marital status, race/ethnicity, educational level, family income, body mass index, smoking status, drinking status, hypertension, diabetes, and cardiovascular disease. Stratified analyses indicated a positive correlation between DCI and epilepsy prevalence in adults with different characteristics. Compared with individuals in quartile 1 of DCI (<40.5%), those in quartile 4 (>55.4%) had an adjusted OR for epilepsy of 1.72 (95% CI, 1.09–2.73, P = 0.02, P for trend = 0.012). Conclusions A high percentage of DCI was associated with an increased prevalence of epilepsy. The risk of epilepsy increased 3.5-fold with a 1% increase in DCI. These results suggest an important role of DCI in the dietary management of epilepsy.