A 59-year-old male was transported to the emergency department by ambulance with complaints of left-sided abdominal pain. Blood gas analysis revealed elevated lactate, and plain computed tomography revealed no bowel ischemic change. Contrast-enhanced computed tomography revealed isolated superior mesenteric artery dissection with mildly stenosed true lumen. The patient was treated with conservative management on admission. Staged fluid intake, oral prescriptions, and diet were commenced with attention to the symptoms. After four days of hospitalization, the patient was discharged with a stable condition. However, the patient returned to our hospital complaining of left lower back pain three hours after discharge. Contrast-enhanced computed tomography revealed an enlarged false lumen with a moderately stenosed true lumen. After a thorough discussion between vascular surgeons and interventional radiologists, conservative management was commenced on the second admission. The clinical course was uneventful, with proof of improved imaging findings.