Pteridines in the wild type of Pyrrhocoris apterus were investigated by high-performance liquid chromatography (HPLC). Five different pteridines were identified: neopterin, biopterin, isoxantholumazine (violapterin), isoxanthopterin, and 7-methylxanthopterin. Biopterin and neopterin have been found in P. apterus for the first time. No qualitative or quantitative differences were observed between pteridine patterns in males and females. The present paper represents the first identification and quantification of P. apterus pteridines using HPLC.