Mucinous cystadenoma is a rare lesion of the vermiform appendix and is seldom diagnosed before surgery, although radiologic and ultrasonographic findings have been reported. We present the case of a 65-year-old female with rheumatoid arthritis who presented with general malaise, poor appetite, fever, and right upper and lower quadrant pain of about one week's duration. Abdominal sonography and computed tomography revealed an 8 x 4 x 3 cm cystic lesion of the appendix. Laparoscopic evaluation confirmed this finding and the lesion was resected without rupturing the tumor during manipulation. Laparoscopic surgery provides the advantages of good exposure and evaluation of entire abdominal cavity, as well as more rapid recovery. It is important to avoid tumor rupture during manipulation, and formation of pseudomyxoma peritonei, in case the tumor is malignant.