The association between oral health and the habits of mothers and their children has received little attention in Nigeria, and the factors that influence this relationship are unknown. The objective of this study was to find out if there is an association between mothers' oral health, oral health practises and their children's. A convenience sample of 288 mother-child pair was recruited consecutively from a tertiary hospital's dental clinic for this cross-sectional study. An interviewer-administered semi-structured questionnaire was utilised to collect socio-demographic data of the child, child’s/mother’s oral health behaviour and practices such as frequency of tooth brushing, tooth cleaning agents, past dental visits, and reason for the dental visit. Dental caries status was determined for children and their mothers using decay, missing due to caries and filled deciduous teeth (dmft) /decay, missing due to caries and filled permanent teeth (DMFT), while simplified oral hygiene index was used to evaluate each participant's oral hygiene. Oral hygiene was classified as poor, fair or good. Data were analysed using Chi-square test and Kappa statistics at p ≤ 0.05. There were 137 male and 151 female children. The mothers' ages ranged from 26 to 65 years, with a mean age of 40.9 years, and the children's ages ranged from 1 to 15 years, with a mean age of 9.0 years. Poor oral hygiene status was found in 16.3% of mothers and 9.4% of children. The agreement between mothers' and children's oral hygiene status was fair (Kappa = 0.215). Mothers with primary or no formal education had higher odds of having children with dental caries than those with tertiary education (OR = 4.22; 95% CI: 1.29, 13.84). The level of agreement between mothers' and children's oral health practises ranged from none (kappa = 0.156 and 0.170) to medium (kappa = 0.339) and moderate (kappa = 0.496). Children whose mothers had a high level of education had better oral hygiene and a lower risk of dental caries. Mothers' oral health status exhibited no discernible effect on their children's oral health status, implying that boosting parents' awareness and attitudes about oral health may have a limited impact on their children's oral health practises and status. Dentists should take advantage of any opportunity to educate paediatric patients on expected and appropriate oral health practices.