Incest is traditionally defined as any sexual activity between family members who are forbidden to marry by law. The inability of apply contemporary interview techniques to the victims and the fact that the family members do not cooperate due to intimacy of the event, make it difficult to determine the actual prevalence of incest cases. In this study, the aim was to determine the prevalence and evaluate characteristics of incest cases. We examined the sexual crime cases have sent to forensic units in 4 years between 2013-2016. Demographic data and the relationship between the victims and defendants were evaluated. The Statistical Package for social Sciences (SPSS) version 20.0 was used to analyze the data. There were 737 sexual crime cases and 57 of them (7.7%) were incest cases. Among these, 15.8% (n=9) of the victims were men and 84.2% (n=48) were women. The average age of victims was 15.3 ± 5.43. We determined that the defendant was mostly the father (n=24, 42.1%). The penetration rate was 33.3% (n=19). Because of late notification and incidental recognition, physical examination findings usually are not detectable. Increasing the education and sensitivity of the individuals who can encounter with these cases like medical staff, teachers, etc. is an important process in the protection of children and their acceptance by society.