During the diagnostic evaluation period for autism or intellectual disability (ID), families of young children are at risk for poor adjustment. The present study aimed to document family quality of life (FQOL), along with associated risk and protective factors, during this critical step of families’ services trajectory. FQOL was measured in a large sample of families of children recently diagnosed with a neurodevelopmental disorder and examined in relation to the type of services received, children’s clinical profile, and family variables. FQOL was related to types of services, children’s challenging behavior, parenting stress, and several aspects of family composition and status. These findings highlight a need for mental health support for parents, coaching interventions for challenging behaviors, and family-centered supports.