Background: A fistula is an abnormal connection between organs or between an internal organ and the skin. Ano-rectal fistulas are chronic inflammatory conditions involving the perianal tissues, creating a pathway between the anal canal and the surrounding skin . These fistulas are more prevalent in middle-aged men than in women, with a male-to-female ratio of 2:1. It is thought that anal gland obstruction leads to abscess formation followed by ruptures through the skin, resulting in fistula development. Many imaging modalities are used to evaluate this area. Magnetic resonance imaging (MRI) has been considered the gold standard procedure over conventional fistulography for perennial fistula assessment. It provides accurate road-maps to select the best surgical approach for a surgeon. It determines the extent of sphincter division, estimates the risk of postoperative incontinence.It is a prospective study of 60 patients (mean age 42.44±13.29years) with perennial fistulas who underwent pelvic MRI with a 1.5 Tesla scanner using multiple Sequences included oblique axial and coronal T1W FSE, T2W FSE. Results: Inter-sphincter fistulas were the most common type of perennial fistula observed based on Parks’ classification. Inter-sphincter, trans-sphincter, extra-sphincter, and supra-sphincter fistulas were found in 32 (60%), 13 (24.5%), 4 (7.5%), and 4 (7.5%) patients, respectively. According to St. James’ classification, 19 (31.7%), 12 (20%), 15(25%), 9 (15%), and 5 (8.3%) patients had perennial fistula grades I, II, III, IV, and V, respectively. The combination of variable MR sequences and MR fistulogram increased the diagnostic validity of MRI examinations. Our results correlated with surgical results (reference standard) with perfect inter-observer reliability. Conclusions: Of all imaging modalities, MRI has become a prerequisite for a successful surgery of a perennial fistula. MRI can identify morphology of fistula, the connection between the fistulous tract and the anal sphincter, fistula wound healing, an active versus chronic scarred fistula, postoperative stigmata, and a perennial fistula from its mimics. MRI with variable sequences and MRI fistulogram are successful combinations that increase diagnostic efficiency with technical safety by avoiding both ionizing radiation and systemic gadolinium.