The aim of this study was to evaluate the correlation between the Child Perceptions Questionnaire 8 to 10 (CPQ8-10) and child-Oral Impact on Daily Performances (child-OIDP) indexes according to their total and item scores, as well as assess the discriminative validity of these assessment tools regarding dental caries and malocclusion among schoolchildren. A sample of 300 children aged between 8 and 10 years answered the questionnaires in two distinct steps. First, half of the sample (G1 = 150) answered the CPQ8-10 and the other half (G2 = 150) answered the child-OIDP. A week after, G1 answered the child-OIDP and G2 answered the CPQ8-10. Dental Aesthetic Index and WHO criteria were used to categorize malocclusion and dental caries, respectively. Descriptive analysis, Spearman's correlation and Mann-Whitney test were performed in this study. The CPQ8-10 and child-OIDP demonstrated a statistically significant and moderate correlation between their total scores. Regarding the discriminative validity, CPQ8-10 demonstrated a significant association between the "emotional status" daily activity and dental caries, and between the "eating", "sleeping", and "studying" daily activities and malocclusion. Concerning the child-OIDP, a significant difference was found only between the "social contact" activity and presence of dental caries. Both instruments were not capable of distinguishing children with and without dental caries and/or malocclusion by their total scores. However, the instruments were able to discriminate between children with and without those oral disorders in different dimensions. Thus, the CPQ8-10 and the child-OIDP demonstrated a different capacity to assess the impact on OHRQoL among schoolchildren.