INTRODUCTION: The adoption of adequate oral hygiene practices is important for the maintenance of good oral health in children. Rural-urban differences in the achievement of this important issue in Peru remain unknown. The objective of this study was to assess rural-urban differences in the proportion of adequate oral hygiene practices in Peruvian children aged less than 12 years, as well as associated sociodemographic factors. METHODS: This was a cross-sectional study of the 2018 Peruvian Demographic and Family Health Survey. Data from 41 330 children aged 1-11 years and their caregivers with complete information on oral hygiene practices were included in the study. Crude and adjusted prevalence ratios and 95% confidence intervals were estimated as measures of association between adequate oral hygiene practices (defined as toothbrushing two or more times a day, having a toothbrush for individual use and changing toothbrushes every 3 months) and sociodemographic variables. RESULTS: The prevalence of adequate oral hygiene practices was 38.3% in the rural area and 57.3% in urban areas. The greatest rural-urban disparities for adequate oral hygiene practices were observed in the age group of 6-11 years (43.4% v 64.1%), those in families in which the head of the household had no formal education (28.1% v 47.3%) or primary education (36.8% v 53.0%), those who had used dental services in the previous 6 months (46.4% v 64.4%) and those residing in the highlands (31.5% v 48.2%). All independent variables were significantly associated with adequate oral hygiene practices in rural areas, except for the jungle region variable and the richest wealth index. CONCLUSION: Four out of ten Peruvian children living in rural areas perform adequate oral hygiene practices compared to six out of ten children in urban areas. Furthermore, inequalities in the adoption of oral hygiene practices favor urban children according to sociodemographic factors. Strengthening of oral health promotion strategies is urgently needed in order to decrease inequalities in the adoption of adequate oral hygiene in children living in rural areas of Peru and countries with similar sociodemographic characteristics.