Perianal fistula is a common disorder with high tendency to recur in spite of satisfactory surgery. Pelvic MRI is the preferable imaging modality for recognition and assessment of perianal fistulas. Aim of the work: To evaluate the effectiveness of MRI in grading of primary perianal fistula and verification of its associated findings in correlation with surgical outcome. Subjects and methods: This prospective study included 30 patients with age range 14–44 years. Preoperative MR grading was correlated with surgical outcome. Results: The sensitivity, specificity, PPV, NPV and weighted Kappa of MR grading in correlation with surgery was 95.8%, 83.3%, 95.8%, 83.3% and 0.79 respectively with P value = 0.000 Conclusion: MRI is a valuable modality for grading of primary perianal fistula and its complications. Accurate pre-operative grading may reduce the surgical complications and possibility of recurrence