Self-development is a central developmental issue in adolescence, there are few studies describing the experiences related to the self in adolescents with autism spectrum disorder (ASD) or attention deficit hyperactivity disorder (ADHD). We conducted semi-structural interviews with 14 adolescents with ASD and three with ADHD to describe the self. As a result of inductive continuous comparison analysis, three concepts "Interest in self and self-realization", "Intentionality and self-transformation", "Unrealized/unnoticed self" were generated. It was suggested that the characteristic perceptions may tend to have difficulty realizing subjective selves. Otherwise, most adolescents realized various sense of self through interaction with others. Nurses should know adolescents' inner world and share their emotions related to their self-recognition in order to provide care that meets important youth developmental needs.