Preschool period is a crucial stage of life in terms of a child's physical, intellectual, emotional, and social development, health promotion knowledge of pre-school caregivers is an important factor that affects children's health. Nursery school is essentially an important place for preschool children to learn healthy eating, adequate hydration, exercise, proper hygiene, teeth care, and controlling emotions with their classmates. Caregivers as educators should make preschool children aware of the dangers of unhealthy behaviors which cause fall, burn, bleeding, and airway obstruction. By teaching children how to stay healthy and safe, caregivers prepare children for these times by teaching them; to deal with accidents and an emergency. Aimed of the present study was to determine the effect of health promotion guidelines on knowledge and practice of caregivers at nursery schools. Convenience sample caregivers contacted by children from 3-6years working at 20 nurseries. The total number of sample was 60 caregivers. Tools of data collection included A structured interview questionnaire & observational checklist and health promotion guidelines to assess Caregivers' knowledge and practice about health promotion of preschool children. Results: There were statistically significant differences in relation to knowledge and practice scores of the caregivers throughout the three phases of the guidelines intervention. Conclusion, it was concluded that guidelines effect on caregivers' knowledge and practice regarding health promotion of preschool children. Recommendation of this study was to provision of health guidelines for caregivers especially those new about health promotion and the needs of preschool children.