Purpose: Self-concept is constructed through individual experiences and knowledge. Adolescents who start to become complicated about finding their identity, self-concept is also needed to help adolescents deal with the development of sexual turmoil, in this case it is called sexual self-concept. One of the factors that influences the construction of sexual self-concept is how fathers involve themselves in parenting. This research aims to determine the influence of father's involvement in parenting on adolescents' sexual self-concept. Method: This research used quantitative method with a total of 347 participants selected. They were teenagers aged 12-18 years who lived in Nganjuk Regency, East Java. Result: It showed that fathers' involvement in caring for adolescents in Nganjuk was at a medium level (91.1%) and teenagers' sexual self-concept was also at a medium level (72.6%). The significance value (Sig.) in the simple linear regression test is 0.000 < 0.05, with the t test result being -7.252 < 1.649, providing information that father involvement in parenting has a significant influence on adolescents' sexual self-concept. Conclusion: Result that show a negative direction indicated limitations in understanding and openness regarding the importance of sexual self-concept in adolescents. Many participants thought sexual self-concept as taboo to be discussed.