BACKGROUND: Genetic variations in ABCB1 gene that encodes P-glycoprotein, the main transporter in the efflux of carbamazepine (CBZ) from the brain cells, can lead to pharmacodynamic and pharmacokinetic variability. Polymorphism of C3435T is widely known to cause protein overexpression that contributes to an increased risk of CBZ resistance. AIM: This study determined the allele frequency distribution of ABCB1 C3435T gene in healthy subjects of the Javanese population as a major ethnic group in Indonesia. METHODS: This cross-sectional study involved 100 healthy volunteers who fulfilled the inclusion criteria. The genotype analysis to detect polymorphism in the targets employed the polymerase chain reaction-restriction fragment length polymorphism method with 5’-TGCTGGTCCTGAAGTTGATCTGTGAAC-3’ as the forward primer and 5’-ACATTAGGCAGTGACTCGATGAAGGCA-3’ as the reverse primer. RESULTS: The frequency of subjects with C allele in ABCB1 C3435T gene reached 53%, higher than that with T allele. CONCLUSION: This finding was nearly the same as that in studies of the populations in China, Turkey, and four countries in the South European continent. It is recommended to conduct further research on the correlation between C3435T polymorphism and CBZ dose variability to provide a comprehensive approach to epilepsy management in patients receiving CBZ.