Résumé : This study aimed to determine if the accreditation process has a positive impact on patient safety and quality of care. A 4 year retrospective and prospective study design was used. A total of 119 performance indicators were collected through various processes and were lately transformed into 81 patient safety and quality indicators. The numbers and rates of hospital mortality, Healthcare-Associated Infections (HAI), medication errors, cardiopulmonary resucutation codes, surgeries and invasive procedures, blood transfusion reaction and adverse events were the main outcome measures. The following areas had the corresponding number of indicators that were found to be sensitive to Canadian accreditation and that significantly improved post-accreditation: Four indicators of perioperative mortality and rates of neonatal mortality per 100 NICU admissions (p<0.05). Healthcare-associated Infections: sixteen out of twenty-six measured indicators (p<0.05). Blood utilization: one out of two measured indicators, i.e., total number of blood transfusion reactions (p<0.05). Surgeries and invasive procedure: two out of seven measured indicators, i.e., total number of unplanned returns to surgery within 48 h and rate of unplanned returns to surgery per 100 operations (p<0.05). Two out of eight measured indicators, i.e., total number of patients who survived after the first CPR and rate of survival after first CPRper 100 coded patients (p<0.05). Two out of eighteen measured indicators, i.e., rate of pressure ulcers per 1000 admissions and total number of the occurrence variance reports (p<0.05). Accreditation has a positive impact on patient safety and quality of care indicators. © Medwell Journals, 2011.