The immunopathology of acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection involves an excessive inflammatory response. Approximately 80% of patients with coronavirus disease 2019 (COVID-19) have a mild illness, 20% require hospitalization, and approximately 5% require intensive care. Neopterin is a macrophage activation marker produced by monocytes and macrophages following activation by interferon-gamma (IFN-γ). It is crucial to determine neopterin levels and evaluate them together with inflammatory, coagulation, and biochemical markers in moderate/mild SARS-CoV-2 infection. The present study compared plasma neopterin and inflammatory as well as biochemical markers of 50 patients with COVID-19 and 38 healthy volunteers without COVID-19. The data of 38 participants did not show statistically significant differences in serum neopterin levels between the mild/moderate COVID-19 and control groups (p=0.259). White blood cell (WBC), neutrophil, lymphocyte, platelet (PLT), hemoglobin (HGB), procalcitonin (PCT), ferritin, prothrombin time (PT), activated partial thromboplastin time (aPTT), international normalized ratio (INR) and lymphocyte CRP ratio (LCR) values were significantly different between the study groups (p<0.001, p=0.001, p=0.001, p<0.001, p=0.014, p<0.001, p=0.001, p<0.001, p=0.004, p<0.001, p<0.001, respectively). According to the ROC analysis, the WBC, PT, Na, and LCR values exceeding the cutoff values may be predictive of COVID-19. Although there were no significant differences in serum neopterin levels between the groups, there were high values in patients with severe SARS-CoV-2 infection in previous studies and these values were maintained for a long time. The present study found that neopterin levels were not elevated in mild/moderate COVID-19 patients.