Hypertension is a growing public health problem in many developing countries including Ethiopia and if left untreated can cause a major risk factor for heart failure, renal failure, stroke and even death. However, its prevention and control has not yet established payable attention. The aim of this study was to assess the main risk factors of hypertension among patients visiting in Adult emergency department of Black lion Specialized Hospital by using risk assessment form that contains 39 structured close-ended questionnaires. It is a descriptive cross-sectional study conducted over a period of three months. Participants aged >18 years were recruited using convenience sampling technique and data was collected by face-to-face interview after verbal informed consent. Additionally, weight, height and Blood Pressure (BP) of participants were measure following standard procedures. Hypertension was defined as having BP ≥ 140/90 mmHg or reported use of regular anti-hypertensive medications. Data was collected by investigator assisted with clinical nurses and then entered into a computer using EPI Info version 3.5.1 and exported to SPSS version 21 for analysis. The study data was analyzed by using statistics such as mean, average and percentages. In this study 254 subjects consisting of 159(62.6%) men and 95(37.4%) women had hypertension. In this study from non modifiable risk factors age, gender, ethnicity, family history, and from modifiable risk factors smoking, alcohol drink, excessive salt intake, Khat chewing, DM,BMI, Physical inactivity, and Psychosocial stressors were observed. In which smoking 35(13.8%) and alcoholic 108(42.5%) might be considerable risk factors only seen in men. Moreover, psychological stressful condition, excessive salt food intake, physical inactivity and BMI were the mainly seen modifiable risk factors in both gender. By this study we concluded that more number of male was observed in the risk factors of hypertension than female and as the age is coming increasingly the probability of the magnitude of risk factors also increase in both gender and mostly avoidable risk factors was observed in high magnitude