Problematic use of the Internet is becoming increasingly important and especially for adolescents, high prevalence rates are reported in many countries. Despite the growing international research activities and the reported prevalence estimates, comparatively very few studies have focused on spontaneous remission and its possible causes. In a risk population of 272 adolescents, we used standardized diagnostic instruments to investigate which socio-demographic and psychosocial characteristics at baseline (at t1) predicted spontaneous remission of problematic Internet use one year later (at t2). The predictors were determined by bivariate and multivariate logistic regression analyses. In the bivariate regressions, we found male gender, higher self-efficacy (t1), a lower level of maladaptive emotion regulation strategies (t1), lower depression (t1), lower performance and school anxiety (t1), lower social-interaction anxiety (t1), and lower procrastination (t1) to predict spontaneous remission of problematic Internet use at t2. In the multivariable analysis, a lower level of maladaptive emotion regulation strategies (t1) was the sole statistically significant predictor for the remission one year later (t2). For the first time, the high relevance of emotion regulation for spontaneous remission of adolescent problematic Internet use was observed. Based on these findings, emotion regulation could be specifically trained and promoted in future prevention measures.