OBJECTIVES: Genetic variations of the tryptophan hydroxylase(TPH) gene and the serotonin transporter linked polymorphic region(5-HTTLPR) polymorphism have been associated with its functional capacity. The authors investigated whether the allelic constitution of the TPH gene and 5-HTTLPR are associated in Korean panic patients. METHODS: 244 Korean patients with panic disorder and 227 normal healthy controls were tested for a genetic polymorphism of TPH A218C and 5-HTTLPR polymorphism. To assess the severity of panic disorder during the last one month, anticipatory anxiety, panic difficulty, panic distress, agoraphobic difficulty and agoraphobic distress were measured with visual analogue scale(VAS) score, STAI-S & T, BDI, SCL-90-R, ASI-R, CGI, PDSS, and HAMD. RESULTS: There was no significant difference in genotype and allele frequencies of TPH A218C and 5-HTTLPR polymorphism between panic patients and controls. Although we observed some differences in genotype and allele frequencies of TPH A218C polymorphism among male subjects, these differences disappeared after Bonferroni correction. And there were no significant differences in clinical variables. CONCLUSION: Our results suggested that there are no association between the genetic polymorphism of TPH gene and 5-HTTLPR with panic disorder.