Background: Early childhood caries may develop as soon as teeth erupt. Promoting oral health care programs is very important and helps to reduce dental caries in young children. The aim of this study was to assess the infant/child oral health (IOH) related knowledge, attitudes, and practices (KAP) of parents in Riyadh, Saudi Arabia. Materials and Methods: A cross-sectional descriptive study was conducted among 327 parents. Visiting the family medicine center at prince sultan military medical city, Riyadh Saudi Arabia. A 39-item questionnaire covering socio-demographic characteristics and questions pertaining to KAP regarding OH care will be used to collect the data. Descriptive statistics, Student’s t-test, one-way analysis of variance, and Scheffe’s test will use for the statistical analysis (p ≤ 0.05). Results: The result showed that the majority of the parents had good knowledge regarding OH, knowledge of cleaning (92.4.%), and knowledge of the amount of sugar (88.1.%). the parent’s age group (30 to 39) years (n =147) reported the highest mean (knowledge, attitudes, and practice) scores among all other age groups with a knowledge mean score of (6.80 ± 1.73), an attitude mean score of (8.86 ± 1.37), and a practice mean score of (5.14 ± 1.86). Female parents showed significantly higher mean knowledge, attitude, and practice scores than male parents. In addition, the middle-income level parents’ group (n = 295) reported higher knowledge mean score compared to the low-income parents’ group (n = 15) with a mean difference of d = 1.15, p = .041. Conclusion: Parents’ knowledge about maintaining oral and dental health care for infants/children was inadequate. Essentially, medical professionals are the initial ones to interact with expecting and new moms. Therefore, need to raise parents’ awareness about oral and dental health for infants/children, through the development and implementation of long-term education and promotions programs.