The authors assessed neopterin, a circulating immune marker of inflammation, as a predictor for COVID-19 among 115 patients with PCR-confirmed SARS-CoV-2 infection and available serum neopterin levels in Austria. In comparison to patients with lower neopterin levels (<45 nmol/L), patients with elevated levels of neopterin (>45 nmol/L) were significantly associated with higher risk of mortality during hospital stay due to COVID-19 (19% vs. 4.5%), need for mechanical ventilation (63.2% vs. 7.5%) during hospital stay, and higher risk for ICU admission (68.4% vs. 10.4%). The results indicate neopterin as a valid predictor for COVID-19, and this knowledge is important in the early identification and case management of patients with higher risk for severe COVID-19 illness.