In view of the increasing concern about methicillin-resistant Staphylococcus aureus (MRSA) infections, we studied the characteristics and outcome of MRSA nasal carriage and infections in our CAPD program. All patients entering into the CAPD program from January 1989 to December 1991 were enrolled into the study. The patients' anterior nares were cultured before the implantation of the catheters. Peritoneal dialysis-related infections were diagnosed based on standard criteria. Data on MRSA nasal carriage, exit-site and tunnel infections and peritonitis were prospectively collected. A total number of 167 patients with 225.9 patient dialysis years were studied with a mean follow-up duration of 16.2 +/- 9.5 months. There were 28 patients with MRSA nasal carriage. The carrier state was unrelated to age, sex and presence of diabetes mellitus. MRSA nasal carriage was associated with a significant increase in the rate of peritonitis (P < 0.01) and exit-site infections (P < 0.01), the number of catheter losses, and CAPD patient dropout (P < 0.001). A total of 30 patients had MRSA infections. In this group, 15 patients had 24 episodes of peritonitis; 20 had 22 episodes of exit-site infections; and 1 had tunnel infection. Fourteen patients had a combination and/or multiple episodes of infections. Treatment of MRSA infections with intraperitoneal vancomycin was unsuccessful in 12 patients (40.0%) resulting in catheter loss. Nine patients (30.0%) dropped out of CAPD after treatment failure for MRSA peritonitis. The patient dropout rate per infection for MRSA infections was comparable to Pseudomonas and fungal infections, but was significantly higher than MSSA infections (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)