Superior mesenteric artery (SMA) dissection is a rare disease. Most of the cases are diagnosed through contrast-enhanced computed tomography. The use of emergent bedside ultrasound has been described to diagnose aortic dissection. However, evidence is limited regarding the use of bedside ultrasound for diagnosing SMA dissection, which is a known risk factor for aortic dissection. We present two case reports: one case of isolated SMA dissection and one case of SMA dissection complicated with aortic dissection. Both cases were initially diagnosed through bedside ultrasound and confirmed through contrast-enhanced computed tomography.