While mental health is an emerging issue in low-income countries, its promotion remains poor, with little context-oriented evidence available. Here we aimed to assess the impact and acceptability/feasibility of a community-based psychodrama intervention involving both adolescents and young adults (AYA) living with HIV (AYALHIV) and without HIV (AYAHIV-). We used a mixed-methods approach, where the quantitative part was based on pre/post questionnaires and the qualitative one on content analysis of semi-structured interviews. Trained community health care workers delivered psychodrama sessions involving AYAs aged 15-24 years once a week between July and August 2023 in Beira, Mozambique. The baseline assessment involved a sociodemographic and three mental health questionnaires: the Mental Health Knowledge Schedule (MAKS), Community Attitudes toward People with Mental Illness (CAMI27), and the Toronto Alexithymia Scale (TAS). We repeated all questionnaires after the intervention and conducted semi-structured interviews. We enrolled 354 AYAs (50.8% female, 45.5% AYALHIV) at baseline; 315 (89.0%) attended the sessions, with a mean participation rate of 94.4%. Overall, 281 (89.2%) completed the post-intervention assessment. MAKS score improved from 44.5 (95% confidence interval (CI) = 44.0-45.0) to 47.1 (95% CI = 46.4-47.7, P < 0.001). Total CAMI27 score showed no significant variation (P = 0.855). Total TAS score decreased from 57.3 (95% CI = 56.1-58.5) to 54.3 (95% CI = 53.0-55.6, P < 0.001). We found no statistically significant interactions between time and sex, age, or HIV serostatus in all questionnaires. For the qualitative part of the study, we analysed 37 semi-structured interviews (43.2% with females, 40.5% with AYALHIV). We identified four areas of intervention impact: peer-to-peer support (30.3%), social empowerment (24.7%), resilience (23.0%), and emotional skills (21.9%). Regarding acceptability/feasibility, perceived scalability (37.2%) and affective attitude (34.5%) were the sub-areas most frequently retrieved in the SSIs. The community-based psychodrama intervention proved to be an effective tool in AYAs' mental health promotion, increasing knowledge and improving emotional awareness through group experience and interpersonal learning. The intervention also showed good acceptability and feasibility in the context of our study.