Syrian refugees in Türkiye show a high prevalence of mental health problems but encounter barriers to accessing mental health services. Group Problem Management Plus (gPM+), developed by the World Health Organization, is a low-intensity psychological intervention delivered by nonspecialist facilitators. This qualitative process evaluation explores the acceptability, feasibility and perceived effectiveness of gPM+ for Syrian refugees resettled in Türkiye, as well as facilitating factors and barriers to its implementation. Twenty-three semi-structured interviews were conducted with gPM+ participants, facilitators, drop-outs, relatives of participants and key informants. Findings showed that gPM+ was well-received for its group-based format, which participants felt fostered social support, and for its content, which they reported may have led to improvements in coping skills and family relationships. Facilitators viewed the intervention as feasible to implement. However, barriers such as participants' economic struggles, practical challenges (e.g., childcare and transportation difficulties) and low mental health literacy impeded engagement. Adapting gPM+ to address social determinants like poverty may be beneficial. The need for booster sessions was emphasized to maintain long-term change and provide deeper learning of the strategies. For sustainable scaling up gPM+ within primary health care, key informants highlighted the importance of training and supervising nonprofessional facilitators and securing governmental support.