One difficulty in monitoring the quality of family--professional partnerships has been the lack of a psychometrically acceptable and sufficiently general instrument with which to assess them. The current work describes the development of the Family--Professional Partnership Scale, which assesses parents' perceptions of the importance of and their satisfaction with family--professional partnerships. Indicators were constructed from qualitative research on families with children with and without disabilities, and the scale was refined across two field tests that included families with children with a wide range of ages and disability types and severity. Both the 18-item overall scale and the two 9-item subscales demonstrated excellent psychometric properties. The possible uses of this scale in future research and service delivery are discussed. (Contains 5 tables and 1 figure.)