The aim of this study was to analyse the level of CEA in peritoneal washings (CEAp) in patients with colorectal cancer (crc) in comparison to the serum CEA level. The study involved 87 patients with crc, the control group included 13 patients operated on due to vascular diseases. At the time of laparotomy, after administration of 200 ml saline, peritoneal washings were collected from the peritoneal cavity. After concentrating, the CEAp level was determined using an immunochemiluminescence assay kit. The cutoff value was set at 100 ng/g protein. The data were analysed using Student t-test, Welch test and Mann-Whitney test. The mean CEA levels in peritoneal washings in patients with colorectal cancer were statistically higher (p < 0.001) than in the control group (except stage A). There was no correlation between CEAp levels and sex, histological type and differentiation, Duke's stage (except D2). The mean CEAp levels were significantly higher in colonic tumour, than in cancer in rectal location (P < 0.03). Positive correlation between CEA level in peritoneal washings and serum was found.