Background: A large body of evidence suggest that parents of young children with autism spectrum disorder or intellectual disability experience low levels of satisfaction with the diagnostic evaluation process. This study sought to document parents' satisfaction with the services of a pilot clinic implemented in Québec, Canada. Method: Two-hundred fifty-nine (259) parents were recruited following their child's diagnosis. A mixed methods approach was used to investigate parents' satisfaction globally and with specific aspects of the assessment process. Results: Parents expressed overall high satisfaction with the assessment process. Parental satisfaction with specific aspects of the assessment process was negatively related to paternal stress, fathers' unemployment and household income and positively related to maternal stress. Conclusions: This pilot clinic could meet parents' needs at this crucial moment in their care and services trajectory. The factors associated with satisfaction in the present study may inform future improvements to its services.