Deinstitutionalisation has influenced the life situation for people with intellectual disabilities, whilst the experiences of health promotion in group homes now are limited. This study aimed to explore aspects important to consider when promoting health amongst persons with intellectual disabilities in group homes, from the perspective of professionals. Semi-structured interviews were conducted with seven professionals and were analysed with thematic analysis. The overarching theme "sense of security" was identified as a prerequisite for health promotion, together with the sub-themes "resources in the organisation", for example, respectful treatment of the residents, and "resources of the residents", for example, meaningfulness and social connectedness. Findings were discussed from the perspective of health assets which is defined as the factors contributing to maintain and sustain health. The importance of strengthening external assets, that is, resources in the society and the organisation, to promote internal assets, that is, residents' individual resources, and ultimately their health, is emphasised.