In this study we looked for CMV IgM and IgG antibodies in the sera of 100 patients (58 women, 42 men) with upper respiratory tract infection. CMV IgG antibodies were positive in 47 (47%) patients and CMV IgM antibodies were positive in 32 (32%) patients. Both CMV IgM and CMV IgG antibodies were positive in 18 (18%) of the patients and in 14 (14%) patients CMV IgM were positive and CMV IgG were negative. With this serological event we discussed the diagnostic value of CMV IgM and CMV IgG in the patients with upper respiratory tract infections.