Adolescents faced with chronic stressors (e.g., financial instability, interpersonal violence) are at heightened risk for developing mental health problems, likely due in part to stressors that interfere with effective emotion regulation. Although mindfulness may help to act as a buffer against the deleterious effects of life stressors, a relatively untested assumption is that adolescents can maintain mindfulness during periods of stress. This paper explores this assumption by investigating the real-time, dynamic relationships among life stressors, mindfulness, and emotion regulation difficulties among adolescents exposed to chronic stressors. Eighty-one participants who were 10-18years old (M=14.33; SD=2.20; 56% male; 57% Non-Hispanic White) completed ecological momentary assessments (EMA) three times a day for 7days and contributed a total of 1186 EMA reports. Multilevel structural equation modelling revealed that the presence (vs. absence) of stressors was associated with lower momentary mindfulness and greater momentary emotion regulation difficulties concurrently and prospectively. Stressors with greater severity were also concurrently, but not prospectively, associated with lower momentary mindfulness and greater momentary emotion regulation difficulties. Findings highlight that exposure to life stressors may degrade momentary mindfulness and emotion regulation. Given that mindfulness and emotion regulation are closely associated with mental health, these results also demonstrate one way that stressors may contribute to health disparities at the micro-level. Going forward, it will be important to investigate methods of helping adolescents learn to maintain mindfulness and adaptive emotion regulation in the face of stressful events. This study was preregistered (NCT04927286).