The authors examined the feasibility and preliminary outcomes of Project Wings Girls' Groups, a school-based mental health promotion program designed to improve well-being in Latina adolescents, as observed in outcomes, including perceived stress, depressive symptoms, coping, and connectedness. This pilot randomized controlled trial compared outcomes over 9 months postintervention for 42 9th and 10th grade adolescents attending two urban high schools. Girls were randomized to Project Wings Girls' Groups, a 16-session facilitated curriculum, including sharing circles, mind-body exercises, and coping skills building or the attention control (i.e., similar format but focused on general health topics). Feasibility of retention and long-term follow-up data collection was demonstrated, with lessons learned for future study. Although not statistically powered, this trial demonstrated findings in the expected direction, including reduced perceived stress and depression and increased connectedness. A trial with sufficient power is warranted to examine Project Wings' effects on mental health problems among Latina adolescents.