Adolescence is characterized as a developmental period of risky decision‐making. During this developmental window there is also a marked increase in actual and perceived stress. Acute stress increases risky decision‐making in adults, but no research has examined this phenomenon in adolescents. In this study, an ecologically relevant approach was used to document daily self‐reports of stress in adolescents and an emerging adult comparison group. Participants visited the laboratory twice: once each when they endorsed a high and low level of stress, where they performed a risky decision‐making task and a response inhibition task. In both groups, participants showed greater risky decision‐making under high (vs. low) stress conditions but no stress‐related effects on response inhibition. The dissociation between decision‐making and response inhibition under stress suggests that, across development, individuals show greater vulnerability to contextual influence in decision‐making domains. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:433–440, 2012.