Rationale & Objective: Peritoneal dialysis (PD)-related peritonitis carries high morbidity for PD patients. Understanding the characteristics and risk factors for peritonitis can guide regional development of prevention strategies. We describe peritonitis rates and the associations of selected facility practices with peritonitis risk among countries participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS). Study Design: Observational prospective cohort study. Setting & Participants: 7,051 adult PD patients in 209 facilities across 7 countries (Australia, New Zealand, Canada, Japan, Thailand, United Kingdom, United States). Exposures: Facility characteristics (census count, facility age, nurse to patient ratio) and selected facility practices (use of automated PD, use of icodextrin or biocompatible PD solutions, antibiotic prophylaxis strategies, duration of PD training). Outcomes: Peritonitis rate (by country, overall and variation across facilities), microbiology patterns. Analytical Approach: Poisson rate estimation, proportional rate models adjusted for selected patient case-mix variables. Results: 2,272 peritonitis episodes were identified in 7,051 patients (crude rate, 0.28 episodes/patient-year). Facility peritonitis rates were variable within each country and exceeded 0.50/patient-year in 10% of facilities. Overall peritonitis rates, in episodes per patient-year, were 0.40 (95% CI, 0.36-0.46) in Thailand, 0.38 (95% CI, 0.32-0.46) in the United Kingdom, 0.35 (95% CI, 0.30-0.40) in Australia/New Zealand, 0.29 (95% CI, 0.26-0.32) in Canada, 0.27 (95% CI, 0.25-0.30) in Japan, and 0.26 (95% CI, 0.24-0.27) in the United States. The microbiology of peritonitis was similar across countries, except in Thailand, where Gram-negative infections and culture-negative peritonitis were more common. Facility size was positively associated with risk for peritonitis in Japan (rate ratio [RR] per 10 patients, 1.07; 95% CI, 1.04-1.09). Lower peritonitis risk was observed in facilities that had higher automated PD use (RR per 10 percentage points greater, 0.95; 95% CI, 0.91-1.00), facilities that used antibiotics at catheter insertion (RR, 0.83; 95% CI, 0.69-0.99), and facilities with PD training duration of 6 or more (vs <6) days (RR, 0.81; 95% CI, 0.68-0.96). Lower peritonitis risk was seen in facilities that used topical exit-site mupirocin or aminoglycoside ointment, but this association did not achieve conventional levels of statistical significance (RR, 0.79; 95% CI, 0.62-1.01). Limitations: Sampling variation, selection bias (rate estimates), and residual confounding (associations). Conclusions: Important international differences exist in the risk for peritonitis that may result from varied and potentially modifiable treatment practices. These findings may inform future guidelines in potentially setting lower maximally acceptable peritonitis rates.