Background <p>This study explores the relationships among Internet addiction, online health information-seeking behavior (OHISB), and cyberchondria.</p> Methods <p>The research was conducted in Yalova Province, Türkiye, with a research sample included individuals aged 18 and over who lived in that province. Data were collected from participating individuals using an online survey.</p> Results <p>The findings demonstrated that Internet addiction had a positive effect on OHISB (β = 0.557). It was also revealed that Internet addiction (β = 0.270) and OHISB (β = 0.442) had a positive effect on cyberchondria. Furthermore, OHISB had a mediating role in the effect of Internet addiction on cyberchondria (β = 0.246).</p> Conclusions <p>This study highlights the existence of significant relationships among Internet addiction, OHISB, and cyberchondria.</p>