High demand has resulted in gaps in autism service provision. Our objective was to explore the association between children's functioning and parents' perceived unmet needs. We conducted a cross-sectional study of 97 families of school-aged children with an autism spectrum disorder. Log binomial regression was used to examine the relative risk for unmet need. Families of children with high functional independence had lower unmet need than families of children with moderate functional independence (RR = 0.81, 95% CI = 0.67-0.99). Those who experienced greater impact of the child's disability had greater unmet need (RR = 1.22, 95% CI = 1.03-1.45). The child's functioning and its impact on the family provide insight into unmet need which may inform service planning.