Infections in transplant recipients are associated with high morbidity and mortality, making their early recognition and treatment particularly important. Abdominal actinomycosis is a rare clinical entity and difficult to diagnose because of its various and nonspecific features. We describe a 57-year-old patient who presented with abdominal actinomycosis simulating colon cancer 6 years after liver transplantation. The main symptom was abdominal pain. Abdominal computed tomography and colonoscopy revealed an intraluminal 4.5 cm mass in the right colon, raising suspicions of a colonic malignancy and leading to surgical intervention. The postoperative pathologic study showed sulfur granules in the resected specimen compatible with abdominal actinomycosis. No signs of recurrence were seen throughout the 6-month follow-up. The literature on actinomycosis infections in immune-compromised hosts is reviewed. This presentation of actinomycosis in a liver transplant recipient has not been described previously, to our knowledge.