Purpose: To assess the quality of toothbrushing of children with intellectual disability (ID). Materials and Methods: One hundred thirty-six children, 68 with ID (SG = study group) and 68 non-ID (CG = control group), were paired. Their caregivers completed a questionnaire about socioeconomic and demographic characteristics and another about oral hygiene habits. The toothbrushing technique and position adopted were documented and the duration of the procedure was measured. A modification of the Simplified Oral Hygiene Index (SM-OHI) was used to classify the quality of brushing as: adequate, when all the teeth had SM-OHI 0 or 1; or inadequate, when at least one tooth had SM-OHI 2 or 3. The Kolmogorov-Smirnov test was used to assess the normality of data distribution for age, duration of brushing and SM-OHI. Fisher's exact test and the chi-squared test were applied to assess the association between ID and oral hygiene habits or characteristics of toothbrushing. To compare the duration of brushing groups, the Mann-Whitney test was applied. Student's t-test for independent samples was applied to compare mean MS-OHI. Results: Mothers were the main persons performing children's toothbrushing in SG. They reported a higher daily brushing frequency, longer toothbrushing duration of children in the SG, SG children had lower SM-OHI scores and were thus rated as having adequate toothbrushing, in contrast to the CG (p 0.001, p 0.001; p = 0.012; p 0.001; p 0.001, respectively). Conclusion: Toothbrushing provided by caregivers for ID children was more effective than toothbrushing carried out by non-ID children of the same age and gender. Keywords: dental plaque, intellectual and developmental disabilities, oral hygiene