Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 2 1 2017 12 11 e4 e4 Pauline Haroutunian Emergency Medicine Department, BIDMC, Harvard Medical School, Boston, USA. Mohammed Alsabri Emergency Medicine Department, BIDMC, Harvard Medical School, Boston, USA. François Kerdiles Emergency Medicine Department, University Hospital of Rennes, Rennes, France. Adel Abdullah Hassan Surgery Department, Thamar University, Thamar, Yemen. Abdelouahab Bellou Emergency Medicine Department, BIDMC, Harvard Medical School, Boston, USA. 2017 12 15 Introduction: Patients’ complaints from Emergency Departments (ED) are frequent and can be used as a quality assurance indicator. Objective: Factors contributing to patients’ complaints (PCs) in the emergency department were analyzed.  Methods: It was a retrospective cohort study, the qualitative variables of patients’ complaints visiting ED of a university hospital were compared with Chi-Square and t test tests. Results: Eighty-five PC were analyzed. The factors contributing to PC were: communication (n=26), length of stay (LOS) (n=24), diagnostic errors (n=21), comfort and privacy issues (n=7), pain management (n=6), inappropriate treatment (n=6), delay of care and billing issues (n=3). PCs were more frequent when patients were managed by residents, during night shifts, weekends, Saturdays, Mondays, January and June. Moreover, the factors contributing to diagnostic errors were due to poor communication, non-adherence to guidelines and lack of systematic proofreading of X-rays. In 98% of cases, disputes were resolved by apology and explanation and three cases resulted in financial compensation. Conclusion: Poor communication, LOS and medical errors are factors contributing to PCs. Improving communication, resolving issues leading to slow health care provision, adequate staffing and supervision of trainees may reduce PCs. https://fem.tums.ac.ir/index.php/fem/article/view/34 https://fem.tums.ac.ir/index.php/fem/article/download/34/38