Cystic fibrosis (CF) is an autosomal recessive condition, mostly diagnosed in infancy. It is uncommon for adults to be diagnosed with CF, especially after the age of 65. Individuals, who are diagnosed later in life, usually have milder disease and single organ involvement which can be challenging for clinicians to diagnose. Adult CF patients are more likely to be pancreatic sufficient. They have predominantly upper lobe bronchiectasis, lower incidence of Pseudomonas aeruginosa compared with Staphylococcus aureus and are more likely to have mutations other than ΔF508.