Introduction: Potato is one of the foods with high nutritional value. High content of nitrate and nitrite in potato is one of the most challenging issues in its consumption and health of individuals. One of the ways to increase the potato quality index is to use cooking processes, and thus, reducing nitrate and nitrite content in the diet, in order to improve the health of the community. Thus, the objective of this research was to evaluate the effect of different cooking method on nitrite and nitrate in potato on human health. Methods and materials: In this descriptive research, 60 potato samples were randomly selected from fruit and vegetable square of Tehran, and the mentioned samples were measured in terms of nitrite and nitrate contents by Greece- Ilosoay method. Then, the considered baking methods were applied and the nitrite and nitrate contents were remeasured. Results: Nitrate and nitrite in the tested samples were 162.3 to 378.7 and 1.7 to 4.9 mg/kg, respectively. The peeling, washing and rinsing of potatoes reduced the nitrate and nitrite contents. Boiling, steaming and frying had a significant effect on reducing nitrate and nitrite contents. Conclusion: The use of boiling, steaming and frying methods can have a significant effect on nitrate and nitrite in potatoes and thus human health.