The suspension of social services in Hong Kong during the COVID-19 pandemic increased the caregiver strain for families of adolescent children with intellectual disabilities, possibly aggravating their family relationships. This article reports on an online Multi-Family Group (MFG) conducted during the pandemic for Hong Kong Chinese families of adolescents affected by mild-to-moderate intellectual disabilities. A thematic analysis of the experiences of the participating service users revealed three positive effects of the intervention model: "improved family relationships," "mutual helpful influences occurring among families," and "a new understanding of family members with intellectual disabilities." The therapeutic group process used to promote family development is illustrated by a group vignette. The challenges and the practical considerations for conducting an MFG online are discussed.