Pylephlebitis is an uncommon complication of uncontrolled intra-abdominal infection that is associated with high morbidity and mortality. We present our experience with a unique case of cecal diverticulitis and septic thrombophlebitis of the superior mesenteric vein that was promptly diagnosed with high-resolution imaging and blood cultures. Antibiotic and anticoagulation therapy was instituted on confirming the diagnosis with magnetic resonance imaging (MRI) to control the infection and prevent propagation of the thrombus. Our case report raises awareness about a rare and potentially fatal condition and provides appropriate imaging supplementation to aid in timely diagnosis.