Abstract： Objective To investigate the CT radiological features of pancreatic cystadenomas and cystadenocarcinomas. Methods The CT scans from 39 patients with pathologically proven cystic pancreatic tumors (21 cases of serous cystadenomas, 12 cases of mucinous cystadenomas, and 6 cases of mucinous cystadenocarcinomas) were retrospectively analyzed. Tumor location, the number of cyst (polycystic or not) , diameter of the largest cyst, features of the cyst wall, partition within cyst, border of tumor, and the relationship between tumors and pancreatic duct were recorded. Results In 21 patients with serous cystadenomas, tumors were located at the pancreatic head and neck areas in 17 cases, at the pancreatic body and tail areas in 5 cases, and 1 case was multiple. All 21 cases were polycystic; the median diameter of the largest cyst was 1.77 cm; calcification was seen in cyst wall or partition in 4 cases and soft tissue was seen in 7 cases; mild pancreatic duct dilatation was found in 10 cases. In 12 patients with mucinous cystadenomas, tumors were located at the pancreatic head and neck areas in 6 cases, at the pancreatic body and tail areas in6 cases; 4 cases were polycystic; the median diameter of the largest cyst was 4.88cm; calcification was seen in 1 case and soft tissue was seen in 6 cases; pancreatic duct dilatation was found in 2 cases and mild duct dilatation was found in 3 cases. In 6 patients with mucinous cystadenocarcinomas, tumors were located at the pancreatic body and tail areas in 5 cases, tumor was located at the pancreatic head and neck areas in 1 case; 4 cases were polycystic; the median diameter of the largest cyst was 5.09 cm; calcification was seen in 1 case and soft tissue was seen in 5 cases; duct dilatation was found in 1 case. In all cases, there was no pancreatic duct communication. After enhancement, the soft tissue and partition of lesion was enhanced to gome extent. Conclusions There are CT radiological features of pancreatic cystadenomas and cystadenocarcinomas. However, there are still some atypical CT appearances that may challenge the diagnosis.