This study explored the combined influences of daily activities and autonomy in activity engagement on adolescent daily positive and negative moods. Ecological momentary assessments (EMA) were used to obtain information about 8th- and 10th-grade students' (N = 517) mood, activities, and situation throughout the day. Participants responded to random prompts on the EMA device and, when prompted, rated mood adjectives and reported on their current activity and perceived autonomy in activity engagement. Mixed-effects regression models examined changes in mood across specific activity categories. Positive mood significantly improved when engaging in numerous activities; negative mood improved during social activities as well as "party" and "hanging out" events but was fairly consistent across other activities. Stronger mood--activity relations were found after controlling for autonomy in activity engagement.