Here we present the results of evaluation of the expression of neural cell adhesion molecules CD56 (NCAM) in serous ovarian adenocarcinoma. The expression was detected in 48.5% cases. Infiltration of tumor stroma and parenchyma with CD8+ and CD4+ lymphocytes was significantly less pronounced in tumors expressing neural cell adhesion molecules; CD3+CD4+CD25+ predominate among CD4+ lymphocytes in CD56+ tumors. CD56+ tumors were lower in size (5.2±0.6, 7.9±0.8 and 10.3±1.5 cm in monomorphic, mosaic, and negative phenotypes, respectively (p=0.05) and were characterized by the absence of cystic component (p=0.012), larger disseminations in the peritoneum (4.2±1.1 and 2.7±0.5 cm; p=0.05), and larger volume of the residual tumor (p=0.018) after surgical treatment. NCAM phenotype of the tumor does not correlate with the stage and differentiation degree of serous ovarian adenocarcinoma.