Hyperphenylalaninemia (HPA) is an inherited metabolic disorder of metabolism of amino acids. This disease is characterized by a high concentration of phenylalanine in blood. Several types of this disease exist, the most frequent being phenylketonuria. It is well known that this disorder, among other clinical features, produces mental retardation, if diagnosis and treatment are not established early. Neonatal screening program with a blood taking on filter paper is an example of excellent and original solution of a HPA diagnostics. Present survey follows development and approaches to laboratory diagnostics of HPA from beginning to the present time.

        Key words: hyperphenylalaninemia, screening and monitoring, dried blood spot, trends in laboratory diagnostics.