Early school-aged children are in a transitional phase from primary to permanent dentition. Established dietary and oral hygiene habits will influence the condition of the oral cavity in the future. This study aimed to evaluate alterations in early school children's dietary and oral hygiene practices during the COVID-19 pandemic and to anticipate potential long-term health implications. This cross-sectional online study involved guardians of Polish children aged 6-10 years, living in Western Poland, who were socially isolated at home during the COVID-19 pandemic. A total of 180 guardians were invited to participate in this study. The questionnaire included 17 questions divided into four different sections-the child's anthropometric data, dietary habits, oral health, and attitude to dental visits. The survey was completed by 106 guardians. The mean (standard deviation) age of the children was 8.12 (0.93) years (range 6-10 years). Overall, 24.5% of the surveyed individuals reported buying healthy products (fresh vegetables, fruit) more frequently during the pandemic. Furthermore, 35.8% admitted to snacking between meals more frequently and 16.0% less frequently. Almost one-quarter of the parents acknowledged that their children were less motivated to maintain oral hygiene during the pandemic and 28.3% declared a lower frequency of visits to the dentist from the outbreak of the pandemic for two main reasons: a fear of coronavirus transmission and economic reasons. In the group studied, the results of the assessment indicate that the COVID-19 pandemic had some effects on oral health that may lead to an increased risk of oral disease development, such as tooth decay in children. None of the respondents noticed an increase in their child's motivation about good oral hygiene despite spending more time at home. The irregularity of follow-up visits for one-third of the respondents hindered preventive measures and the continuation of dental treatment.