It is very important for the teachers to know the sexual abuse and harassment as they are people who know and best communicate with the individual after their families and to transform the inappropriate behaviors of the students towards their personal sexual behaviors, against one another or their peers into good behaviors in order to prevent future negative effects. Knowing the appropriate and non-appropriate sexual behavior of students with mental deficiencies will guide the determination of the content of the program. The purpose of this study was to examine the opinions of the adolescents with mental deficiencies on their in-school experiences and on the in-school training and abuse issues. Six teachers who provided education in schools of students with mental deficiencies were involved in the research. The results showed that teachers had inadequate education about sexual education both during university education and in-service training, and that the students showed inadequate behaviors in the classroom environment due to lack of information and education deficiencies. It is also seen that the teachers do no have enough knowledge about the mentally retarded adolescents showing proper sexual behavior.