Background: The families of a population sample of people with Down's syndrome (DS), and of their non-disabled controls, have been followed since early childhood, and the families have now been seen again as their sons and daughters reached age 30 and 35 years. Methods: A semi-structured interview schedule was used, including items from the handicaps, behaviour and skills schedule [L. Wing, "Acta Psychologica Scandinavica", Suppl. 285 (1980) 241] and from Holmes' thesis ("The Quality of Life of Mentally Handicapped Adults and Their Parents", 1988, PhD Thesis) relating to leisure and social life and experience of services. Results: Most parents, now in their late 60s, reported good health and a satisfactory social life. Mothers' mean stress scores were slightly higher in the Down's syndrome group than in the controls: possible explanations for this are discussed. Only one factor relating to the offspring with Down's syndrome could be shown to influence stress. Few adverse effects on the siblings were identified. Conclusions: The study is in agreement with others in showing families of older people with Down's syndrome to be well-adjusted and not unduly stressed.