Introduction. Generalized anxiety disorder (GAD) is one of the most common types of anxiety disorder in epilepsy population, comprising 21.9%, that would further impair patients' quality of life. Generalized Anxiety Disorder-7 (GAD-7) is the only screening tool for GAD that has been validated in patients with epilepsy (PWE). It is a self-reporting instrument that can be completed in less than three minutes; hence, its usage is appropriate in primary healthcare and neurology outpatient clinic. This study aimed to obtain a valid and reliable Indonesian version of GAD-7, assess its accuracy, and finally evaluate the prevalence of GAD in Indonesian PWE along with its contributing factors. Methods. A cross-sectional study was conducted in Cipto Mangunkusumo General Hospital, Jakarta. The GAD-7 was translated and adapted using World Health Organization (WHO) steps. Validity, reliability, test-retest reliability, and diagnostic accuracy were evaluated. Then, epilepsy outpatients were screened for GAD using the Indonesian version of GAD-7. Results. Internal validity and reliability for Indonesian version of GAD-7 were satisfactory with validity coefficient of 0.648 to 0.800 (p<0.01) and Cronbach's alpha value of 0.867. The best cutoff value to detect GAD in Indonesian PWE was >6 with the sensitivity, specificity, negative predictive value, and positive predictive value of 100%, 84.4%, 100%, and 55.8%, respectively. ROC analysis showed the area under the curve of 0.98 (95% CI: 0.96-0.99). The total subjects screened with the validated Indonesian version of GAD-7 were 146, and 49% were screened as having GAD. Sociodemographic and clinical characteristics had no statistically significant association with the presence of GAD. Conclusion. The Indonesian version of GAD-7 was a valuable screening tool to detect GAD in PWE. GAD was screened in a quite high proportion of PWE. Sociodemographic and clinical characteristics were not proven to play role in its development.