cancer diagnostics and novel therapies. Glycan microarrays are effective methods for analyzing glycans and antiglycan antibodies, which are immobilized arrays of oligo- or poly-saccharides on different substrates, making them a promising class of oncological biomarkers. Blood serum samples from patients (n = 203) with ovarian cancer (OvaCan) and healthy volunteers were analyzed using a glycan microarray containing 63 immobilized glycans to determine changes in anti-glycan IgG and IgM antibody profiles in OvaCan. Levels of anti-glycan IgG and IgM antibodies in OvaCan statistically differed from levels in healthy donors: the most prominent statistically significant difference for anti-glycan IgG antibodies was found for 6-O-su-Lec (AUC = 0.657, Se = 48.0 %, and Sp = 73.3 %). The AUC values for certain glycans investigated in diagnosing OvaCan indicated a fingerprint consisting of IgM antibodies to specific glycans, and the most specific anti-glycan IgM antibodies were Ley (AUC = 0.625, Se = 98.0 % and Sp = 45.0 %). The potential of these serological biomarkers to distinguish between OvaCan and other malignancies is still an unresolved issue that requires more large-scale studies to confirm and validate the use of these biomarkers in the diagnosis of different types of cancer.