People with severe mental disorders have impaired health, and low self-care skills, while presenting a higher risk of developing infections, other chronic diseases, and higher mortality compared to the general population. The majority of health promotion interventions targeting them are methodologically designed based on the subjective assessments of health professionals. This qualitative study aims to assess the health promotion needs among people with severe mental disorders, as well as to explore their perceptions regarding the concept of co-production. Two focus groups were conducted with 18 adults, diagnosed with severe mental disorders receiving services from community mental health settings in Attica, Greece. The data was analyzed using content analysis. Regarding health promotion needs, five themes emerged: psycho-education, rights, settings and services, community education, and physical health. Concerning the co-production concept, five themes emerged: equality, collaboration, inclusion, peer support, and feedback. The findings of this study could be used to design a health promotion program for people with severe mental disorders based on the principles of co-production.