Background  Although grandparents are recognized as an important source of support for families of children with intellectual and other disabilities, there has been very little research in this area. The aim of the present paper is to present a brief overview of the literature, and to present data from a preliminary study of relationships between parental stress and grandparent support and conflict. Methods  Sixty‐one parents of children with Down's syndrome (34 mothers and 27 fathers) completed questionnaires on grandparent support and conflict. Parents also completed the Friedrich Short Form of the Questionnaire on Resources and Stress (QRS) with scoring amended to include a depression sub‐scale. Results  The main findings were: (1) grandparent support and conflict were associated with mothers' but not fathers' ratings of stress on the QRS, and (2) both grandparent support and conflict made independent contributions to the prediction of mothers' stress on at least one dimension of the QRS. Conclusions  Practical implications of the results for interventions designed to encourage grandparent support for families are discussed. Issues for further research and methodological problems with the study are also identified.