Background: Globally, approximately about 1.25 million people die annually from road trafficrnaccident (RTA). Moreover, about 20 to 50 million people sustain nonfatal injuries as a result ofrnroad traffic crashes. Evidence from global safety report shows that, the trend of road traffic injury inrndeveloped countries is decreasing while accident trend in developing countries including Ethiopia isrnnotably increasing. This trend will go further owing to increased motor vehicle ownership and usernassociated with economic growth in developing countries.rnObjective: to determine injury severity of Road Traffic accident and associated factors amongrnvictims referred to selected public hospitals of Addis Ababa based on Haddon Matrix.rnMethods and Materials; the study was conducted in public health facilities of Addis Ababa,rnEthiopia from March 1 to May 10, 2017. Hospital based descriptive cross sectional study designrnwere implemented to select 363 victims using systematic random sampling method. Interviewerrnadministered structured questionnaire were used to collect the data while Kampala trauma score IIrnwere applied to measure injury severity of RTA victims. The collected data was cleaned andrnentered into Epidata version 3.1 and exported to SPSS Ver.21 for analysis. Multiple logisticrnregression models were used to indicate the association between variable.rnResults; A total of 363 individual sustained road traffic injuries were included to the study. Thernprevalence of severe injury among road traffic accident victims was 36.4%. Victims type AORrn0.42(95% CI; 0.20-0.88), helmet use AOR 4.7(95%CI; 1.04-21.09), presence of multiple injuryrnAOR 3.88(95% CI; 2.26-6.65), vehicle type AOR2.14(95% CI; 1.01-4.52), Vehicle occupantrnseating place AOR3.9(1.18-12.080),crash type AOR 0.48(95% CI; 0.24-0.93), lighting conditionrnAOR 1.93(95% CI; 1.01-3.65), availability of traffic signals and tools AOR1.95(95% CI; 1.18-rn3.24), tight traffic police control AOR 0.49(95% CI; 0.27-0.88) and person extricate the victimsrnAOR 0.33(95% CI; 0.13-0.83)were factors significantly associated with injury severity level.rnConclusion and Recommendation; Results reported in this paper suggest the need forrnimmediate and pragmatic steps to be taken to curb the wanton destruction of lives that arernoccurring on the roads. In particular, there is urgent need to introduce road safety interventions tornaddress this public health hazard that is claiming the lives of economically productive age group.rnKey words: Road traffic accident, injury severity, Haddon Matrix, Ethiopia