Background: It is known that pre-school children are an innocent group, as attention and care of oral health is given the necessary priority to determine the state of oral health for future generations. Generally, the kids in the age less of five spend the all-time with parents and guardians, especially mothers, even they go to the nurseries, it is in these early years that 'initial socialization' and through which early childhood habits are acquired. Objective(s): This study aimed to evaluatemothers' attitude and practices toward oral health of children under 5 years old at al-Nasiriya city. Methodology: A descriptive study design carried out between October 27th, 2021 to March 30th 2022 on mothers of children under 5 years at primary health care center in Al-Nasiriyah city, to evaluate the mother attitudes and practice about children under five years oral health.The research sample includes (310) mothers of children under five years. They are selected by using non-probability sampling (convenience sample). Results: Results observed that all mothers had responded at a moderately level concerning the attitude aspect. And that of the practice results observed that mothers’ respondents had responded at a low level, while it came to evaluate two items for each a moderate, and high levels. Conclusion: There is a connection between mothers’ attitude and practices Occupation, and Source of Information. Recommendation: Encourage mothers to regular visit to dentist clinic and assess the children oral cavity and identify any health problems.