Cystic fibrosis is a progressive monogenic autosomal recessive disease with multisystem readings. The locus of the gene responsible for the development of cystic fibrosis was identified by analyzing the pedigree of a family with affected members, comparing patterns of polymorphism of RFLP markers, cloning the region with the gene of interest using chromosome walking and chromosome jumping methods and identification of coding sequences within the region. The gene responsible for disease is named cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR protein participates in the active transport of chloride and hydrogen carbonate ions through the cell membrane. Mutations within the CFTR gene reduce its functionality and cause cystic fibrosis. Depending on the impact on CFTR protein biosynthesis, mutations are divided into six classes. The pathophysiology of the disease is based on the disruption of water transport through the membrane due to dysfunctional ion transport. Thick secreted mucus is a suitable substrate for the settlement of microorganisms and blocks many channels in the body. Gene therapy offers a permanent cure for cystic fibrosis by correcting the genetic defect of the CFTR gene. The CRISPR-Cas system or peptide nucleic acids are examples of gene therapy successful in the experimental correction of cystic fibrosis and are possible forms of gene therapy that will find wider application in treatment.