We reviewed all peritonitis over the last decade to compare patient outcomes on automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD). There were 327 episodes of peritonitis in 198 patients during this period. The rates were 0.57 per patient-year and 0.55 per patient-year on APD and CAPD respectively. For 52% of the episodes, the patients were admitted and managed with a mixture of CAPD and APD, so that no further analysis of outcomes was performed. For 48% (158) of the episodes, the patients were treated as outpatients and remained on their existing modality: 49 on APD and 100 on CAPD (9 catheter-related peritonitis excluded). In the APD group, 5 catheters were eventually removed for recurrent or refractory peritonitis. One other patient died in conjunction with peritonitis. Therefore, the adverse outcome was 12% on APD (6/49 episodes). In the CAPD group, 5 catheters were removed for refractory or relapsing peritonitis (including 1 for peritonitis with a leak). One other patient with fungal peritonitis died. Therefore, the adverse outcome on CAPD was 6% (6/100 episodes), which is not statistically different from the 12% on APD (p = 0.21). In summary, the incidence of peritonitis was similar on APD and CAPD, with one half the patients in each group requiring admission. In peritonitis treated on an outpatient basis, failure was twice as high with continuation of APD as compared with continuation of CAPD, but the difference was nonsignificant. Further studies on managing peritonitis in patients on APD are needed.