Objective To investigate the diagnosis and treatment of pseudomyxoma peritonei (PMP) and provide a reference for diagnosis and treatment of PMP.Methods The clinical features,laboratory examinations,treatment and outcomes of 8 PMP misdiagnosed cases were analyzed with recent relevant reference.Results Ultrasonography,CT,peritoneal cytological examination,tumor markers results are helpful for diagnosis of PMP.PMP will be confirmed and classified by pathological examination after operation.Complete cytoreductive surgery (CRS)or major debulking surgery (MDS) of the tumor combined intraperitoneal chemotherapy and systemic chemotherapy,eight patients in seven cases survived 4-71 month range,one patient died of respiratory failure of pulmonary infection after the third operation.Conclusions Ultrasonography,CT,peritoneal cytological examination,tumor markers tests help avoid misdiagnosis of PMP before operations.Intraoperative findings follow after PMP,CRS or MDS should be executed in the operation or the next time.Intraperitoneal chemotherapy and conventional chemotherapy can improve survival in patients with PMP and prolong their survival time.