This study examined family quality of life (FQOL) of Turkish families who have children with intellectual disabilities (ID) and autism. To research the perceptions of FQOL and relevant predictive relationships, data were gathered from 3,009 families who have children with ID and autism. The data were collected by using a Socio-demographic Family Information Form, Beach Center Family Quality of Life Scale, and the Family Support Scale. The FQOL and subdomain perceptions of families who have children with ID and autism were slightly above a moderate level; the highest perceptions were in the Family Interaction domain, and the lowest perceptions were in the Physical/Material Well-Being domain. We computed significant positive correlations between overall FQOL perception and family social support domains as well as between overall FQOL perception and sociodemographic variables. In the prediction of overall FQOL perception, the variable that mostly explained total variance was emotional support. For the covariates of care support, household/income, information support, socioeconomic status, age of child, type of disability, and affiliation support, the ability to predict FQOL was weak. Conversely, age of mothers, employment status of mothers, and material support domain were not important predictors in FQOL.