Background and aims: Gaming may function as maladaptive coping strategy in youth with internet gaming disorder (IGD). Ecological Momentary Assessment (EMA) enables real-time monitoring of emotions and behavior. This study investigates the temporal dynamics of stress, negative emotions, craving and gaming behavior applying EMA to male youth with IGD during periods of varying gaming intensity and compared to healthy controls (HC). Methods: 29 males diagnosed with IGD, aged 15-25 years, and 26 matched HC were included. Participants underwent diagnostic assessment followed by one week of EMA via smartphone. The group with IGD continued EMA for two additional weeks: one week of unrestricted gaming and one week of restricted gaming. Data on gaming time, stress, negative emotions and craving were collected twice-daily on weekdays and up to sixteen times daily on weekends. Results: Participants with IGD exhibited significantly higher levels of depression, anxiety, stress, gaming time and craving compared to HC. While gaming time varied between unrestricted and restricted gaming conditions, craving, stress and negative emotions remained stable. In male youth with IGD, gaming was followed by a short-term reduction of stress and negative emotions. However, increased stress and negative emotions were subsequently followed by decreased gaming time. Discussion and conclusions: This study indicates a complex, bidirectional relationship between gaming, stress and negative emotions. Although gaming provides short-term emotional relief, the association with elevated levels of depression, anxiety and chronic stress highlights its role as maladaptive coping strategy. Conversely, negative emotions and stress do not necessarily seem to increase gaming time.  Kulcsszavak: ecological momentary assessment, EMA, internet gaming disorder, stress, coping