The study compared biochemical and hematological parameters in ambulatory adult patients with and without serological evidence of previous SARS-CoV-2 infection between August and December 2020. IgG and IgM antibodies were detected by two independent immunochromatographic tests, with only those with positive reactivity in both being seropositive. The total seroprevalence of antibodies against SARS-CoV-2 reached 22.3%. No significant differences in hematological parameters were found between seropositive and seronegative individuals. Seropositive patients had significantly lower HDL cholesterol levels (median 40.5 vs. 45.3 mg/dL; p=0.009), especially in women. Liver enzymes were higher in seropositive, including AST (median 30 vs. 24 U/L; p=0.007) and ALT (median 32.5 vs. 20 U/L; p=0.001), more pronounced in men. There were no differences in glucose, total cholesterol, LDL-C, triglycerides, ALP, or total bilirubin. The findings suggest the need for biochemical monitoring after SARS-CoV-2 infection in at-risk populations.