⋄ Objective Loss of residual renal function (RRF) in peritoneal dialysis (PD) patients is a powerful predictor of mortality. The present study was conducted to determine the predictors of faster decline of RRF in PD patients in Taiwan. ⋄ Methods The study enrolled 270 patients starting PD between January 1996 and December 2005 in a single hospital in Taiwan. We calculated RRF as the mean of the sum of 24-hour urea and creatinine clearance. The slope of the decline of residual glomerular filtration rate (GFR) was the main outcome measure. Data on demographic, clinical, laboratory, and treatment parameters; episodes of peritonitis; and hypotensive events were analyzed by Student t-test, Mann–Whitney U-test, and chi-square, as appropriate. All variables with statistical significance were included in a multivariate linear regression model to select the best predictors ( p < 0.05) for faster decline of residual GFR. ⋄ Results All patients commencing PD during the study period were followed for 39.4 ± 24.0 months (median: 35.5 months). The average annual rate of decline of residual GFR was 1.377 ± 1.47 mL/min/m2. On multivariate analysis, presence of diabetes mellitus ( p < 0.001), higher baseline residual GFR ( p < 0.001), hypotensive events ( p = 0.001), use of diuretics ( p = 0.002), and episodes of peritonitis ( p = 0.043) independently predicted faster decline of residual GFR. Male sex, old age, larger body mass index, and presence of coronary artery disease or congestive heart failure were also risk factors on univariate analysis. ⋄ Conclusions Our results suggested that diabetes mellitus, higher baseline residual GFR, hypotensive events, and use of diuretics are independently associated with faster decline of residual GFR in PD patients in Taiwan.