Environmental contamination by endocrine-disrupting chemicals (EDC) has been a major focus of recent research and policy discussions. EDC-suspected man-made chemicals used as raw materials or plasticizers have been shown to elute from plastic products. To examine whether the dialysate for continuous ambulatory peritoneal dialysis (CAPD) is contaminated with EDC, we determined bisphenol A (BPA), nonylphenol (NP), di-(2-ethylhexyl)phthalate (DEHP) and di-n-butyl phthalate (DBP) in the pre-used dialysate and in the peritoneal effluent from renal failure patients by gas chromatography/mass spectrometry. Concentrations of BPA, NP, DEHP and DBP were 0.02–0.23 ppb (μg/l), 0.09–0.22, 1.1–3.7, and <0.1–2.1 ppb, respectively, in the pre-used dialysate, and <0.01–0.07, <0.1–0.45, 0.35–1.23, and 0.42– 1.76 ppb, respectively, in the effluent, from which the maximal daily contamination of BPA and NP by CAPD was estimated at the microgram level and that of phthalate esters at the 10-μg level. These concentrations are far less than the toxic dosage reported so far, so that CAPD is unlikely to contaminate patients seriously.