Internet gaming disorder (IGD) is a rapidly expanding psychopathological manifestation necessitating further research and clinical attention. Although recent research has investigated relationships between user-avatar and excessive gaming, little is known about the interplay between IGD and avatar self-presence and its dimensions (i.e., the physical, emotional, and identity bond developed between the user and the in-game character). The aim of the present pilot study was twofold: (i) to investigate the associations between physical, emotional, and identity aspects of self-presence associate and IGD severity, and (ii) to assess IGD variations longitudinally in relation to the three dimensions of self-presence (i.e., proto-self-presence, core-self-presence, and extended-self-presence). The sample comprised 125 young adults aged between 18 and 29 years who underwent either (i) three offline measurements (1 month apart, over 3 months) or (ii) a cross-sectional online measurement. Regression and latent growth analysis indicated that the initial intensity of the physical, emotional, and identity self-presence aspects associated with IGD severity, but not to its longitudinal change. Overall, young adult gamers may exhibit higher IGD risk and severity when the experience of physical, emotional, and identity bonding with their in-game character is pronounced. The implications surrounding treatment and preventative policy recommendations are further discussed.