To determine whether -344T/C CYP11B2 promoter polymorphism affects serum aldosterone levels and whether this polymorphism is an indicator of eGFR decline in patients with chronic kidney disease. -344 C/T CYP11B2 gene polymorphism analysis was performed in 96 adults with stages 1-5 CKD by using polymerase chain reaction. Serum aldosterone levels were measured at baseline and at 1.5-year follow-up. The primary outcome was the annual eGFR decline and the secondary outcome was the occurrence of cardio-cerebrovascular events. The genotype distribution of -344T/C SNP in the patients with CKD was: CC (9.4%), CT (53.1%), and TT (37.5%), nearly similar to the healthy non-CKD individuals as reported. Mean aldosterone levels were highest in the TT group and lowest in CC group (p = 0.036). Serum aldosterone level also showed a negative correlation with baseline eGFR in patients with eGFR >60 mL/min (r = -0.403, p < 0.001). The mean annual eGFR decline ratio was highest in the TT group and lowest in the CC group (p = 0.011). The incidence of cardio-cerebrovascular accidents was significantly higher in the TT group than in the CC and CT groups (p = 0.033). -344T/C promoter polymorphism of CYP11B2 modulated aldosterone levels in patients with all stages of CKD and was predictive of annual eGFR decline in CKD stages 3-4. In addition, the -344 T allele appeared to be an independent predictor of cardio-cerebrovascular events.