Purpose: To investigate the perceptions of parents/caregivers about the impact of oral conditions on the oral health-related quality of life (OHRQoL) of children/adolescents with autism spectrum disorder (ASD) compared to the perceptions of parents/caregivers of children/adolescents without ASD. Methods: A comparative cross-sectional study was conducted involving 80 children/adolescents with ASD three to 16 years of age matched by sex and age with 80 children/adolescents without ASD and their parents/caregivers. Clinical examinations were performed for the diagnosis of dental caries experience (DMFT/dmft), clinical consequences of untreated dental caries (PUFA/pufa), visible plaque (VPI), bleeding on probing (BPI), malocclusion and traumatic dental injury (TDI). Parents/caregivers answered a questionnaire addressing sociodemographic characteristics and the Brazilian version of the Parental-Caregiver Perceptions Questionnaire (P-CPQ), which measures OHRQoL from the perspective of parents/caregivers. Data analysis involved the Wilcoxon test, chi-squared test and Poisson regression. Results: Dental caries experience impacted OHRQoL in the group with ASD regarding the total P-CPQ score (p < 0.001) as well as the "oral symptoms" (p = 0.011) and "wellbeing" (p < 0.011) domains. No differences were found between the perceptions of parents/caregivers of children/adolescents with ASD and perceptions of parents/caregivers of children/adolescents without ASD (p = 0.721). Conclusion: Dental caries experience can have a negative impact on the OHRQoL of children/adolescents with ASD.