The focus of this study was to investigate the impact of family sex education in secondary schools on students in Kogi State, Nigeria. The descriptive survey design was used for the study. A total of 1,960 secondary school students were drawn by stratified random sampling from 40 schools within Kogi State, Nigeria. Three research questions were generated for the study. Data collected using a researchers' structured questionnaire were subjected to statistics of frequency counts and percentage. The results revealed that students have sexual problems, misuse of sex, high teenage pregnancies and abortion and inadequate information on sex. Among the recommendations made include the provision of adequate counseling and enlightenment programmes for students, teachers and parents on the dangers of sex misuse and abuse, and the implementation of the law against sex abuse of any form, and full enforcement of the child right act of Nigeria.