The aim of this grounded theory study was to explore late-adolescents' process of sexual development along with their information- and support-seeking behaviors in a Swedish context. Data were collected in semi-structured interviews with late-adolescents aged between 18 and 21 years in high schools in central Sweden. The results showed that late-adolescents' sexual development involved seeking for knowledge, discussing norms and attitudes, learning through interactions, and growing through practice and experience. Information- and support-seeking behaviors were observed throughout their development. This study highlights that, in order to be able to provide adequate help and support, healthcare professionals need to have an awareness of the changing information and support needs of adolescents in our constantly changing and diverse society.