This article describes our five-year experience of continuous ambulatory peritoneal dialysis (CAPD) with bag exchanges performed without use of a face mask. The study took place in the renal unit at a university hospital. All patients admitted to the CAPD program from February 1995 to March 2000 were trained to perform bag exchanges without use of a face mask. Occurrence of peritonitis episodes was the outcome of interest. We evaluated 94 patients (52 women, 42 men) with a mean age of 48 +/- 21 years and a total follow-up of 50,502 patient-days. During that time, 79 episodes of peritonitis occurred in 46 patients, for a peritonitis rate of 0.57 episodes/year. The most frequently isolated micro-organisms were Staphylococcus epidermidis in 20 patients (25.3%) and S. aureus in 11 patients (13.9%). Renal transplantation was the major cause of drop-out [23 patients (43.4%)], followed by peritonitis [14 patients (26.4%)], death due to cardiovascular complications [9 patients (17.0%)], loss of ultrafiltration [2 patients (3.8%)], and other causes [5 patients (9.4%)]. The probability of being free of peritonitis at 12 months was 0.60, and at 60 months, 0.37. Peritonitis rates during the study period were not different from those reported by other centers, supporting the hypothesis that routine use of a face mask during CAPD bag exchange may be unnecessary.