Cystic fibrosis (CF) is a common inherited disorder in caucasians. The estimated incidence of CF in Asians varies from 1:10,000 to 1:12,000. Indian data is restricted to few case reports. The gene for CF is located on the long arm of chromosome 7 at position 7q13. There are more than 300 identified mutations in CF. The basic defect in CF is a mutational change in the gene for chloride conductance channel. Failure of chloride conductance by epithelial cells leads to dehydration of secretions that are too viscid and difficult to clear. The disease is characterized by abnormal secretions in the respiratory, gastrointestinal and reproductive tract and sweat glands. The common clinical manifestations include meconium ileus in neonatal period, recurrent lower respiratory tract infections (pseudomonas pneumonia, bronchiectasis), steatorrhoea, azoospermia, and in late stages hepatobiliary and endocrine pancreatic dysfunctions. The diagnosis of disease is established by clinical criteria and sweat chloride concentration more than 60 mEq/L. Facilities for DNA diagnosis of common CF mutations are now available in India. The treatment of CF includes early diagnosis, daily clearance of respiratory passages, appropriate antibiotic therapy, aerosolised recombinant human DNase and antibiotics, and nutritional supplementation. The latter include changes in diet composition, pancreatic enzyme supplementation and vitamins and trace mineral supplementation. Gene therapy for the pulmonary manifestations is being tried in a number of centres abroad. Other considerations include heart lung transplantation and ameloride inhalation therapy.