BACKGROUND The risk of intravascular radiocontrast to residual renal function (RRF) in patients on peritoneal dialysis (PD) remains largely unknown. OBJECTIVE This study sought to estimate the effect of coronary angiography on RRF in patients on PD. METHODS All patients at the VA Pittsburgh Healthcare System and University of Pittsburgh who underwent coronary angiography between 1993 and 2005 while on PD and who had RRF measured prior to angiography were identified retrospectively. For patients without a postprocedure RRF recorded, medical records were reviewed to determine whether anuria had developed. The longer-term rate of loss of RRF among cases was compared with a composite rate of decline in RRF among cases before angiography and matched controls. RESULTS Twenty-nine patients with a mean preprocedure RRF of 4.4+/-3.2 ml/min/1.73m(2) were evaluated. Of these patients, 23 (79%) had postangiography RRF assessments (mean clearance 3.4+/-3.0 ml/min/1.73m(2)). One of the remaining six patients definitely became permanently anuric following angiography, one was lost to follow-up, and there was no postprocedure RRF assessment in four others. The rate of decline in RRF in the cases was similar to the composite rate (0.07 ml/min/1.73m(2)/month vs. 0.09 ml/min/1.73m(2)/month, p=0.53) CONCLUSIONS The risk for permanent anuria in patients on PD undergoing coronary angiography appears to be quite small. Patients who do not develop anuria following coronary angiography have the same gradual rate of loss of RRF as other patients on PD. Providers should be vigilant in protecting RRF in patients on PD undergoing coronary angiography.