This paper was carried out to study the effect of using whole oat grains in cookies processing for secondary school girls to prevent overweight and obesity. In order to achieve this aim, three formula of cookies A₀, A₁, and A₂ were formulated, rich in dietary fiber, prepared form whole oats grains and wheat flour (WO :WF) with different ratios 100% WF, 50: 50% (WO :WF), 100% WO. Physical, chemical properties and sensory evaluation of prepared cookies mixtures were studied. Results revealed that physical evaluation of cookies samples showed that prevalence rates were increased with the increasing of oats ratio 43.6 to 53.28. There was no significant (p≥0.05) difference in Overall acceptability between cookies samples. Regarding to the chemical properties of prepared cookies samples, the control cookies sample contains, fiber 0.68 %, protein 11.21% fat 18.92% and carbohydrates 62.38%, and the percentage of fiber increases   from 0.68 to 2.64% with increasing ratio of whole oat. Also obtained results found that the calculated calories of prepared cookies decreased with the increase of oats from 426.09 to 421.82 Kcal. Finally, it could be concluded that nutritious and healthy cookies could be prepared by replacing up to 100% wheat flour with whole oats grains without negative effects on the overall acceptability of oat cookies.