Introduction and aim. Phenylketonuria is the most prevalent inherited metabolic disorder. Early detection and prompt treatment can prevent serious neurological consequences. This has become possible thanks to the implementation of newborn screening programmes. The objective of this review is to provide readers with a comprehensive understanding of the phenylketonuria and the role that neonatal screening plays in the protection of public health. Material and methods. A review of the literature was conducted using the PubMed database, with the search period encompassing the most recently published scientific sources. Analysis of the literature. This article presents phenylketonuria as an example of an inherited metabolic disorder, outlines the treatment options, and discusses the potential implications of hyperphenylalaninemia. Furthermore, it also delineates the various aspects of health that are influenced by newborn screening. Conclusion. Phenylketonuria represents a significant health problem in the population. The development of screening tests has transformed healthcare, including improvements in quality of life, prognosis, and reductions in the number of comorbidities in patients. It is essential to disseminate knowledge among the society about the importance of newborn screening tests in order to enhance awareness and prevent refusal to participate.