Congenital chloride diarrhea is a genetically determined disease caused by a mutation in the SLC26A3 gene, located on chromosome 7 at the 7q31 locus. It encodes a transmembrane transport protein that is normally present in the colon and small intestine, where it is responsible for the absorption of chloride. Congenital chloride diarrhea is an autosomal recessive congenital disease. Currently, different types of mutations in SLC26A3 have been described. If the gene is defective, protein synthesis is disrupted, as a result the absorption function of the intestinal epithelium decreases, which is accompanied by the development of diarrhea syndrome. This article describes a clinical case of congenital chloride diarrhea. Clinical case demonstrates a late diagnostic, despite the presence of characteristic signs of the disease even at the stage of intrauterine development of the fetus. Early diagnosis and timely start of treatment determine a favorable prognosis of the disease and guarantee the preservation of the patient’s quality of life.