The present study aimed to explore the potential moderating effects of extracurricular study habits, internet usage duration, gender and emotion regulation skills on internet addiction of preservice teachers. The sample consisted of 492 preservice teachers (308 female) from 10 different institutions in Turkey, who voluntarily provided data. The findings revealed that emotion regulation skills, particularly reappraisal, interacted with daily internet usage time in predicting internet addiction. High levels of reappraisal emotion regulation were linked to lower levels of internet addiction, regardless of the duration of internet use. Conversely, for individuals with lower reappraisal abilities, a positive correlation emerged between internet usage time and internet addiction. Furthermore, extracurricular study habits significantly contributed to the prediction of internet addiction in a positive way, as evidenced by both regression and correlational analyses. These findings underscore the importance of considering emotion regulation alongside study habits and other physiological factors to better understand and address internet addiction in preservice teachers. The implications of the findings for educational policy and teacher education are discussed.