Introduction: We wish to integrate an adverse events reporting system in a Tunisian University Hospital. However, before the implantation of this system, it is important to identify the factors that may influence the reporting, so it is primordial to conduct a study which aims to determine influencing factors of adverse events reporting according to the perception of health care professionals. Method: a cross-sectional descriptive study was conducted between July and September 2014, using a questionnaire which was developed in the light of reason's works on safety culture (1990; 1997), and the Pffeifer, Manser and Wahner (2010) model of influencing factors of adverse events reporting. This questionnaire was self-administered to 46 physicians, 21 health technicians, 65 nurses and 18 practical nurses working in a Tunisian Hospital. Data analysis was conducted using SPSS. Results: The main obstacles identified were: lack of staff training (78.7%) and lack of precision on the types of events reported (76.7%). However, the three main facilitators are the establishment of a safety culture (88%), the commitment of decision makers in the safety culture (81.3%) and the absence of punishment (78, 7%). Conclusion: a policy and managerial consideration of the main factors influencing reporting of adverse events, as well as suggestions from health professionals, is necessary to ensure a good adoption of the reporting system by healthcare institutions in Tunisia.