Aim: To assess the knowledge and oral health practices of a selected population of mothers in order to develop appropriate oral health promotion program for children in the area. Method: A cross sectional study was carried out among a convenient sample of mothers who attended two well-baby clinics-a tertiary and a primary health care centre in Lagos, Nigeria. A questionnaire requesting personal information, previous exposure to and source of oral health education (OHE), knowledge of oral health, diet and oral hygiene practices was administered. Results: There were 104 participants, aged 21 -46 years (mean 32.01 ± 4.85 years); 58.7% had received OHE, 23.1% from electronic media, 22.1% dentist and 9.6%, doctor or nurse. Only 44 (42.3%) had attended the dentist, 5 (4.8%) in <1 year and 10 (9.6%) within 1 -2 years. Most younger mothers, compared with older mothers had knowledge of fluoride (x 2 = 8.51, p = 0.014). Only 44 (42.3%) and 20 (19.2%) respectively believed the type of baby food and supplement affect the child's teeth. Conclusion: Participants in this study showed inadequate knowledge of preventive oral health care. Regular OHE is recommended for mothers at the well baby and immunization clinics where they can be easily reached by health professionals.