Five institutionalized patients with Alzheimer-type dementia were observed (video-recorded) during meals. The aim was to assess their meal behaviour and social interaction. The results showed that when the patients ate without the participation of staff, the two least demented patients became 'caregivers' in the group and helped the three most demented patients to eat. When two mental nurses joined the group, the patients dropped their roles as helpers. The conversation in the group could be characterized as incomplete, with short sentences and a lot of breaks. Sixty-three per cent of all comprehensible utterances concerned food and eating and almost all conversation concerned the present.