Actinomyces infections can create diagnostic dilemmas and be mistaken for malignant tumors.Case report and review of the pertinent English-language literature.A 44-year-old man who had undergone an appendectomy for perforated appendicitis presented three years later with an abdominal wall mass. He had been treated postoperatively for an abdominal wall infection with Actinomyces. Given his poor response to antibiotics and a diagnostic work-up that could not definitively rule out a malignant tumor, a wide local excision was performed. Microscopic examination revealed sulfur granules consistent with Actinomyces.Although the current recommendation is to treat Actinomyces infections with antibiotics, there may be a role for surgical intervention if the response to antibiotics has been suboptimal or a malignant process cannot be ruled out.