Sexual assault is one core reason in developing PTSD. Little research has been conducted to rnmeasure prevalence of PTSD on sexually assaulted victims and why some victims develop PTSD rnand others do not. The objective of this study was to see the prevalence of PTSD and to identify rnor illustrate risk factors that are related to developing PTSD. The research design of the study rnwas both Quantitative and Qualitative. In the quantitative research method, the survey included rnall individuals who could be available. Descriptive qualitative research design was used to rnillustrate individual experiences of risk factors. The study participants are individuals who have rnbeen sexually assaulted and who are currently getting service or treatment at EWLA, Abrhot, rnGandhi, OPRIFS, AWSAD and IFSO in Addis Ababa. PTSD CheckList 5 which is a self -report rnquestionnaire and key informant semi-structured interview was used to collect data from the rnstudy participants. The data were analyzed using frequency, percentage, through Statistical rnPackage for the Social Sciences version 16.0 statistical packages and thematic analysis. The rnresults of this study showed that, PTSD is 46.48% prevalent. The major risk factors for PTSD rnwere sex, gender, educational status, type of contact with perpetrator, number of perpetrator, rnpast medical illness, substance abuse, economical and marital status of the victimâ€™s family, rnparenting style, sub cities the victims came from, past psychiatric illnesses and negative rnchildhood experience such as abuse. It is important that research continue on the topic of rnprevalence of PTSD and its risk factors in individuals who have been sexually assaulted.