Objective: In this multicenter, retrospective study, we recruited a total of 138 Korean patients (male : female = 96 : 42) with XLAS from 121 families who had been diagnosed from Jan 1985 to Jan 2021 in 13 tertiary  centers in Korea. The genetic diagnosis was confirmed by Sanger or next-generation sequencing. The patients were divided into three groups according to the genotypes: Group (GP) 1=missense (n=45; Gly:non-Gly=36:9) or in-frame mutations (n=1); GP 2=splicing mutations (n=12); GP 3=frame-shifting or nonsense mutations (n=38).  Methods: In 96 male, the median age of presentation was 5.1 years and the presenting symptoms were asymptomatic urinary abnormality (n=25), gross hematuria (n=24) or nephrotic syndrome (n=19). During follow-up, 54 (56%) developed chronic kidney disease grade 5 (CKD G5) by the median age of 20.0 years despite using renin-angiotensin system inhibitors in nearly all the patients. SNHL was detected in 50%. Although the ages of developing CKD G5 showed no significant difference among the three groups, kidney survival rates were significantly different (the median age of GP 1, 29.0  years; GP 2, 21.4 years; GP 3, 20.6 years, P=0.014). The frequency of SNHL was 33% in GP 1, 58% in GP 2, and 68% in GP 3 (P=0.002). In 42 female, the median age of presentation was 3.0 years, and 9 (21%) developed CKD G5 by the median age of 29.2 years. SNHL was accompanied in 14%. The kidney survival of the female patients was not correlated with genotypes.  Results: Kidney survival rate and frequency of SNHL showed correlation with genotype in male patients but not in female patients, consistent with previous reports.  Conclusions: Objective: Many clinical studies have elucidated the correlation between genotype and phenotype in male X-linked Alport syndrome (XLAS), whereas no association has been found in female XLAS. Here, we analyzed genotype-phenotype correlation in Korean XLAS. Methods: In this multicenter, retrospective study, we recruited a total of 138 Korean patients (male : female = 96 : 42) with XLAS from 121 families who had been diagnosed from Jan 1985 to Jan 2021 in 13 tertiary  centers in Korea. The genetic diagnosis was confirmed by Sanger or next-generation sequencing. The patients were divided into three groups according to the genotypes: Group (GP) 1=missense (n=45; Gly:non-Gly=36:9) or in-frame mutations (n=1); GP 2=splicing mutations (n=12); GP 3=frame-shifting or nonsense mutations (n=38).  Results: In 96 male, the median age of presentation was 5.1 years and the presenting symptoms were asymptomatic urinary abnormality (n=25), gross hematuria (n=24) or nephrotic syndrome (n=19). During follow-up, 54 (56%) developed chronic kidney disease grade 5 (CKD G5) by the median age of 20.0 years despite using renin-angiotensin system inhibitors in nearly all the patients. SNHL was detected in 50%. Although the ages of developing CKD G5 showed no significant difference among the three groups, kidney survival rates were significantly different (the median age of GP 1, 29.0  years; GP 2, 21.4 years; GP 3, 20.6 years, P=0.014). The frequency of SNHL was 33% in GP 1, 58% in GP 2, and 68% in GP 3 (P=0.002). In 42 female, the median age of presentation was 3.0 years, and 9 (21%) developed CKD G5 by the median age of 29.2 years. SNHL was accompanied in 14%. The kidney survival of the female patients was not correlated with genotypes.  Conclusions: Kidney survival rate and frequency of SNHL showed correlation with genotype in male patients but not in female patients, consistent with previous reports.