Objectives: This study aimed to analyse activities and projects to promote healthy lifestyles carried out in Baixo Alentejo (Portugal), and to understand, from the perspective of health professionals (nurses, and other health professionals in primary health care) and representatives of municipalities, the factors that influence the development of these activities and projects to promote healthy lifestyles. Method: Exploratory-descriptive study using the qualitative inquiry method. A non-probability sample of fourteen professionals (from primary health care and municipalities) who have a key role in the development of interventions to promote healthy lifestyles was considered appropriate. Semi-structured interviews were used and their content was analysed. Findings: We present the results of the preliminary analysis where five categories emerged: 1. Interventions to promote healthy lifestyles; 2. Effectiveness of interventions in the adoption of healthy lifestyles; 3. Factors that influence the development of interventions to promote healthy lifestyles; 4. Environment facilitator of healthy choices, and 5. Nurse's role in healthy lifestyles promotion. Conclusions: The interventions are directed mainly at children and the elderly, and are usually developed by the health sector, but municipalities also have an active role. An interesting range of inter-professional and inter-sectoral collaborative partnerships in health promotion intervention was described, mostly initiated by primary care teams. Municipalities and other community organizations also seek the health sector as a preferred partner in health promotion interventions. Community participation is one of the most frequently mentioned strategies to increase the effectiveness of health promotion interventions, however, there are difficulties in community empowerment and a lack of culture of participation in people and communities. Regarding the factors that influence the development of interventions to promote healthy lifestyles, these may be related to the participants, the professionals, the intervention, or the organizations. The role of nurses was evidenced by all respondents, recognizing that nurses play a key role in the development of promotion interventions of healthy lifestyles. [ABSTRACT FROM AUTHOR]