Introduction: Physical inactivity is a major contributor to the increasing levels of obesity and other serious medical conditions among children and adolescents worldwide. A major factor in this increase is lack of awareness of mothers' regarding the Physical Activity (PA) of their children. Aim: The current study aimed to identify the degree of knowledge and awareness of Saudi mothers' regarding their children's physical activities, which will be useful for improving physical education, health programs, and eventually children's health care. Materials and Methods: A total of 342 mothers attending a vaccination clinic, well-baby, or women's health clinic participated in the study, in which questionnaire was used to assess the awareness regarding PA. Results: The majority of mothers agreed that they have a crucial role in motivating their children to engage in PA, but was not aware of current recommendations. Conclusion: Awareness of Saudi mothers' regarding their children's PA was exceedingly low. Creating awareness of children's PA is essential.