OBJECTIVE The genetic background of idiopathic central precocious puberty (ICPP) is not well understood. The genetic activation of pubertal onset is thought to arise from the effect of multiple genes. Familial ICPP has been reported suggesting the existence of monogenic causes of ICPP. Kisspeptin and its receptor are found to be involved in gonadotropin-releasing hormone (GnRH) secretion and puberty onset. Mutations in their genes, KISS1 and KISSR, have been suggested to be causative for ICPP. METHODS ICPP was defined by pubertal onset before 8 years of age in girls, and a pubertal luteinizing hormone (LH) response to GnRH testing. Twenty-eight girls with ICPP were included in the study [age at diagnosis was 5.72±2.59, with a mean bone age advancement of 1.4 years (-0.1 to 2.8). Height at onset of therapy in SD score was 0.90±1.48 for age]. Luteinizing hormone-releasing hormone test was performed in all subjects, and all of them had a pubertal response (LH 20.35±32.37 mIU/mL; FSH 23.32±15.72 mIU/mL). The coding regions of KISS1 and KISS1R were sequenced. RESULTS No rare variants were detected in KISS1 or KISS1R in the 28 subjects with ICPP. CONCLUSIONS We confirmed that mutations in KISS1 and KISS1R are not a common cause for ICPP.