The Beach Center Family Quality of Life Scale is an internationally validated instrument for measuring family outcomes. To revise the scale for better alignment with the Family Quality of Life theory, the authors excluded non-outcome items in this revision. In this study, we examined reliability and validity of the revised scale (i.e., the FQoL Scale-21) and its scores for Taiwanese families of children and youth with intellectual disability and developmental delay (age 0-18). Results from 400 Taiwanese respondents suggested that the FQoL Scale-21 has the potential to be used as an indicator of positive outcomes in intervention evaluation, policy making, and service delivery.