Preservation of residual renal function (RRF) is an important goal in peritoneal dialysis (PD). The present study explored the factors conditioning RRF decline in a PD population. We studied 148 consecutive patients. Age, sex, diabetes, previous renal replacement therapy time and modality [hemodialysis (HD), renal transplantation (RT), or PD first], peritoneal transport, PD prescription [automated (APD) or continuous ambulatory], and peritonitis were investigated as possible determinants of RRF decline. In 22 patients (15%), PD was started after RT. Residual renal function was not significantly different between patients who started PD as their first option and those who started after RT, either at baseline or after 1 year on PD. Baseline dialysate-to-plasma creatinine was also similar between those groups. Transfer from HD was the single significant predictor of baseline anuria [odds ratio (OR): 6.3; p < 0.001). After the start of PD, diabetes was the only predictor of anuria (OR: 2.5; p = 0.02). Age, sex, reason for PD, PD after graft failure, peritonitis, use of APD, and fast transport were not predictors of anuria. Despite slow tapering of immunosuppression, peritonitis-free survival was not shortened in patients who started PD after RT. Diabetes was a determinant of the time course of RRF decline in PD. Peritoneal dialysis after RT failure offered short-term RRF protection that was similar to that seen in PD-first patients.