Background: 60% of adolescents in Indonesia claim to have had premarital sex, and 50% of them have been diagnosed with HIV and AIDS. The lack of sex education influences the prevalence that occurs in adolescents. Besides, factors affecting sex education in adolescents are lack of access to information regarding sex education. Objective: This study aims to explore the needs of parents in providing sex education to adolescents. Method: This research is qualitative research with a descriptive method. This study was conducted through in-depth interviews with 9 informants, namely parents with adolescent children aged 10-15 years in Kalirandu, which was determined by purposive sampling. The data validity was measured using member checks, thick descriptions, and peer debriefing. In analyzing the data, this research used open code software 4.03. This research has received an ethical permit issued by the ethics committee of FKIK UMY number 008 / EC-KEPK FKIK UMY / I / 2022. It was declared ethically feasible in accordance with 7 (seven) WHO standards 2011. Result: The results showed that parents needed materials regarding sex education. They also needed media to convey the material, knowledge about providing or delivering sex education, and socialization, such as sex education counseling programs. Conclusion: The factors of free sex in adolescents included a lack of knowledge of sex education. Therefore, parents play a key role in providing sex education to adolescents to provide understanding so they can avoid free sex violating norms.