The incidence of rare diseases is approximately two cases per 10,000 people. Today, in most cases, orphan diseases are caused by genetic disorders, less often - some forms of oncological, oncohematological, infectious disorders. These conditions have a severe and chronic course, accompanied by a decrease in quality and a reduction in the life expectancy of patients. Aim - describe a clinical case of an rare disease that is referred to as Zellweger spectrum disorders. Literature review and analysis of clinical-anamnestic and laboratory-instrumental methods of research of a 6.5 years old girl. The given clinical case, namely Zellweger spectrum disorders (ZSD), is a hereditary autosomal recessive disease characterized by nonspecific clinical manifestations and phenotype, which complicates timely diagnosis and delays symptomatic, and in some cases prognostically favorable treatment. Molecular genetic research makes it possible to finally confirm this disease. Therefore, at the slightest suspicion of this pathology, it is worth investigating the level of long-chain fatty acids, plasmalogen of erythrocytes, intermediate metabolites of bile acid synthesis, or carrying out genetic sequencing. Further studies of this condition are carried out in the world in order to obtain new methods of treatment and improve the quality of life of patients. The presented clinical case of a rare disease, which belongs to ZSD, confirms the need for alertness of family doctors and pediatricians in order to timely diagnose and correct rare diseases in children.