Background: Non-compliance to GLUTEN-FREE DIET (GFD), due to less of knowledge and inappropriate nutritional behaviors, is associated with an increase in disease progression and long-term complications in patients with celiac. The aim of this study was to determine the effect of nursing consultation on knowledge and practice of patients with celiac for adherence to GFD. Methods: 100 patients with celiac disease participated in this clinical trial study. They were divided into two groups (control and experimental) randomly. The patient in experimental group received a nursing counseling intervention and the control group received the celiac association routine care. Data collection tool was a reasearcher-made questionnaire including demographic variables and questions for assessing knowledge and practice for adherence to GFD. Data were collected before and after 7 weeks of intervention. Data were analyzed (descriptive and analytic) using SPSS software. Findings: Before the intervention, the level of knowledge and practice of the subjects in adherence to GFD was 91. 12 ± 8. 63 and 54. 12 ± 5. 30 in control group and 91. 18 ± 9. 43 and 52. 94 ± 6. 06 in experimental group, respectively. After counseling, there was an increase in the knowledge and practice scores in GFD adherence in the experimental group (127. 58 ± 1. 80 and 73. 78. ± 3. 24, respectively) compared to the control (92. 62 ± 7. 43 and 54. 82 ± 6. 13, respectively) (P < 0. 050). Conclusion: Nursing counseling results in greater adherence to GFD by raising knowledge of patients about celiac disease and related risk factors as well as the benefits of changing behavior and performance. The importance of the role of nursing counseling in following up the GFD was emphasized in this study.