Objectives <p>Adolescent pregnancy has garnered public interest due to its implications for health, social dynamics, and economic outcomes. Fatherhood contributes to the formation of the identity of young men, particularly during their transition to adulthood. Prenatal care presents a valuable opportunity to involve adolescent fathers in parenting and supporting their pregnant partners. This study aims to investigate how adolescent fathers perceive fatherhood while attending a specialized prenatal clinic.</p> Methods <p>This qualitative study focused on 14 expectant adolescent fathers aged up to 19 years, recruited from a specialized prenatal care clinic at a tertiary hospital in Brazil. Employing a purposive sampling strategy, we utilized in-depth interviews, sociodemographic questionnaires, and field diaries for data collection. Data analysis involved content analysis, contextualized within the framework of Health Psychology.</p> Results <p>We raised four categories: (1) “Myself, a dad?!”: reactions to a positive pregnancy test and the young men’s concepts of fatherhood; (2) The imagined relationship with the baby and expectations for the future; (3) The new dynamics in the relationship with the female adolescent during pregnancy; and (4) The influence of the social circles on the development of fatherhood: the family of origin and the friends.</p> Conclusions <p>The findings underscore the importance of integrating adolescent fathers into healthcare initiatives, addressing critical life-course topics such as family planning, bonding with the child, social support networks, and assistance for adolescent women. These insights highlight the potential for prenatal care settings to offer comprehensive support and guidance to young men navigating their parental roles.</p>