Background: Cancer rectum is one of the most common causes of cancer all over the world. Early diagnosis depends on presenting symptoms and screening followed by diagnostic studies , the most widely used are colonoscopy and barium enema. Recently, the MRI examination of the rectum has evolved as the standard technique in the assessment of cancer rectum having multiplanar capabilities and high tissue contrast imaging. Aim: The purpose of this study was to examine all patients with rectal tumors regardless of size, level within the rectum, or degree of stenosis. Methods: Sixty patients with primary rectal cancer were studied .the age range was 20 to 65 years with the mean age 40 years .Female to male ratio was three to two . The diagnosis of rectal carcinoma in these patients was established based on their symptomatology, clinical examination, proctoscopy and biopsy. The lesions were located 3-12 cm from the anal verge .patients were selected from outpatients clinic and department of surgery at Al Orman oncology hospital. Results: MRI was proved to have high accuracy in the assessment of the rectal wall infiltration and pelvic organ involvement which is about 97.9 %. And also has high accuracy in the assessment of perirectal and pelvic lymph nodes involvement which is about 94.6 % as compared to the post-operative pathological results. Conclusion: Preoperative MRI has a golden standard value in the establishment of the best treatment strategy.