Background/aim Emerging evidence on lowering dialysate temperature suggests a cardiorenal protective effect of dialysate cooling (CD) against dialysis-induced ischemia in hemodialysis (HD) patients prone to intradialytic hypotension (IDH). Whether this benefit of CD could be extended to incident HD populations without baseline IDH to preserve residual kidney function (RKF) is unknown. Patients and methods One hundred incident HD patients were randomly assigned to receive either incremental CD less than or equal to 36°C (intervention, N=50 patients) or standard-temperature (ST) dialysate (control, N=50 patients) for 12 months. The primary endpoint was to test the safety and efficacy of CD to preserve RKF. Results By the end of 12 months, CD patients showed less decline in estimated glomerular filtration rate compared with standard-temperature patients (6.2 vs. 4.6 ml/min/ 1.73 m2 , P=0.025); in addition, Cox regression analysis showed that CD was an independent variable for the preservation of RKF (P=0.044, hazard ratio: 0.478, confidence interval: 0.23–0.89). CD was well tolerated, with less fatigue and IDH; however, coldness, shivering, and discomfort were significantly higher in the CD group. Conclusion In incident HD patients without baseline IDH, cooled dialysis might help preserve RKF with a reasonable safety profile. Further studies are warranted to explore these findings.