Background & objectives: Understanding relationships between dietary factors and prevention of diabetes is increasing. Pre-diabetic patients should have an appropriate diet. The overall goal of this project was to investigate the effect of application of Trans-theoretical Model based education on enhancing nutritional behaviors in pre-diabetic individuals in Yazd city. Methods: This experimental-trial research with control group was conducted on randomized samples of 220 pre-diabetic patients referred to Yazd city health centers using Trans-theoretical Model to improve nutritional behaviors controlling diabetes. In order to achieve project goals, a multi-dimensional questionnaire was designed based on the model constructs and requirements and filled in a long with 72-hour recall and food frequency forms by participants before and after intervention. Results: Before intervention, measurements of stage of change construct revealed that majority of participants (i.e. 86.4% of experimental group and 79.1% of control group) were in the pre-action stages (pre-contemplation, contemplation and preparation) in terms of nutritional behaviors. However, 21.4% of the experimental group and 73.4% of the control group were observed in the pre-action stages after the intervention. Conclusion: Type 2 diabetes is a global crisis that threatens health and economy of all nations. Scientific evidence shows that the vast majority of type 2 diabetes can be prevented through improving diet and lifestyle modification in pre-diabetic patients.