CONTEXT: School-based mindfulness and yoga studies generally measure stress-related outcomes using quantitative measures. OBJECTIVE: This study answers the following research questions: How do youth define stress and in what ways, if any, was a mindful yoga intervention helpful to youth during stress experiences? DESIGN AND SUBJECTS: To explore youths' own perspectives on stress, stressors in youths' lives, and perceived changes in responses to stress post-intervention, we conducted focus group discussions with 22 middle school students from low-income urban communities following a 16-week mindful yoga intervention. RESULTS: Using thematic analysis, the following three themes emerged: (1) youth conflated stress with negative emotions; (2) peer and family conflicts were common stressors; and (3) youth reported improved impulse control and emotional regulation following the intervention. Study findings have implications for refining intervention content (e.g., discussions of stress), as well as informing the selection and development of quantitative measures for future research on stress and stress responses in urban youth.