Actinomycosis is an anaerobic infection caused by actinomycetes, which are part of the normal flora in the intestinal, anal and genital tracts. Although the infection is often cured medically with appropriate antimicrobial therapy, diagnosis is usually made surgically. We report the case of a 41 year-old woman with intra-abdominal mass secondary to extensive actinomycosis involving the hepatic flexura. She required emergency surgery during which the mass was excised. A review of the literature on abdominal actinomycosis during the last 20 years is reported. Emergency surgery has been rarely described in this condition. Although the incidence of actinomycosis has decreased, the abdominal form has been observed with increasing frequency: it could be the result of prolonged use of intra-uterine device. Abdominal actinomycosis is an extremely rare infection that can mimic multiple disease processes and requires accurate diagnosis for successful therapy.