Introduction. Lesions of the peritoneal and retroperitoneal cavities are heterogeneous and include vascular disorders, inflammations and tumors.   Aim of the study: To present the preliminary results regarding the types of peritoneal and retroperitoneal lesions.   Material and methods. The clinicopathological aspects were examined in all consecutive cases diagnosed in 2015 at Department of Pathology of Clinical County Emergency Hospital of Tirgu Mures, Romania.   Results. From the 672 cases, 491 were diagnosed with peritonitis, 125 with tumor lesions, 54 with vascular disorders and two patients presented hydatic cysts. Our of 125 tumors, 116 were metastatic (92.80%) and 9 (7.20%) were diagnosed as primary tumors. In 19 out of 125 tumors, ascites was associated. Metastases were predominantly diagnosed in women (n = 69; 59.48%) with a median age of 64.17±13.05 years, whereas peritonitis mostly affected the male gender (n=281; 57.23%) with a median age of 39.53±26.54 years.   Conclusion. The type of peritoneal and retroperitoneal lesions are related to the patients’ gender: peritonitis is more frequent in males, whereas metastases predominantly affects females in their pre-menopausal or menopausal period. Ascites does not always occur in patients with peritoneal carcinomatosis.