Injuries (unintentional and intentional) are the main cause of death and disability worldwide, including Jordan. The main purpose of this hospital-based retrospective study was to identify characteristics, causes, and risk factors of unintentional injuries and violence among all adult patients who approached the Accidents and Emergency department because of injury in Northern Jordan. Data were collected retrospectively from four major hospitals from January 2008 to January 2013. A total of 2425 Jordanian individuals who accessed and were treated by the four hospitals were included in this study. The findings show that the majority of patients who approached the Accidents and Emergency departments in the four hospitals were males (n = 2044, 87.16%) versus females (n = 301, 12.8%). Violence was the most common reason of injury (70.66%), followed by road traffic crashes (23.21%). The most common anatomical locations of reported injuries were the head (38.74%), followed by abdomen/pelvis and lower back, among males and females (9.93%). Violence had a high significant effect on the site of injuries. Patients who had been injured to the head because of a stab wound or fighting were substantially over-involved in head injuries, with injury rates 3.88 and 7.51 times higher than those who had been injured to the head due to gunshot, respectively. Even patients who had been injured to the head because of assault show much higher involvement in injury risk than non-assault patients (Odds Ratio = 8.46). These findings highlight the need for a large national study to confirm the findings. It also draws attention to the importance of public awareness and to special injury prevention programs that not only focus on saving lives and lessening the number of injuries, illnesses, and fatalities, but also to limit the social and economic burden of injury among adults in Northern Jordan.