A 43-year-old man complained that during the previous 2 years he had experienced a number of episodes of hepatic colic. After examination, we diagnosed a symptomatic cholelithiasis with a sclerosed and atrophic gallbladder. He underwent laparoscopic surgery. During the operation, we observed multiple peritoneal tumors that appeared to be metastases of a gallbladder cancer. The histological study demonstrated a benign chronic cholecystitis accompanied by multiple peritoneal cystic mesotheliomas, an extremely rare tumor in men. The etiology of cystic mesothelioma is still unclear. It has been suggested that they are really multiple inclusion cysts that result from a proliferative reaction within the peritoneal tissue; their continued proliferation might be caused by the continued persistence of an inciting factor. However, in our patient, the proliferation appeared to be related to an extensive peritoneal tissue reaction to the chronic gallbladder inflammatory process. We did not use sclerosing therapy because we had resected the gallbladder and most of the visible lesions laparoscopically; therefore, we had most likely eliminated the potential source of the inciting factor. Because it is very difficult during laparascopy to differentiate these benign quistic mesotheliomas from peritoneal metastases or tuberculous lesions, it is debatable whether the surgeon should continue or terminate the laparoscopic procedure in these ambivalent and potentially risky circumstances.