A qualitative study was undertaken to investigate the perceptions and experiences of insulin-treated people with diabetes mellitus. Seven people were randomly selected from an opportunistic sample and interviewed either at home or on hospital premises. The subjects comprised four women and three men (age range 20-72 years). The study found that hypoglycaemia plays a significant role in the lives of these subjects and that concern over having a hypoglycaemic attack is constantly present. All subjects had suffered at least one attack which had potentially serious consequences and six did not always recognize the warning signs of an impending insulin reaction. Only one of the subjects said they would be happy to live alone.