Improved clinical care has led to a dramatic increase in life expectancy for people with cystic fibrosis (CF). As they live longer, people with CF are therefore developing secondary complications. Cystic fibrosis-related diabetes (CFRD) is the commonest extrapulmonary complication of CF. Insulin deficiency is the primary defect in CFRD, but insulin resistance and impairment of the enteroinsular axis play contributory roles. CFRD affects 9% of people with CF aged 5 to 9 years, 26% aged 10 to 20 years, and up to 50% by the age of 30. The presence of CFRD is associated with accelerated decline in pulmonary function, poorer growth and nutritional status, and increased mortality. The need for early detection of abnormal glucose handling in CF is clear since it is linked with clinical decline. Patients with CFRD may be asymptomatic for many years, so it is recommended that screening be commenced at 10 years of age. Although oral glucose tolerance test is recommended, it is well recognized that early glucose handling abnormalities will not be detected and the chance to intervene early may be missed. Many centers are therefore using continuous glucose monitoring to refine the diagnosis and investigate real-life glycemic control. Future research will hopefully widen our understanding of the pathophysiology of CFRD and therefore the treatment options available. There are clearly some promising results suggesting the use of oral agents may prove beneficial in treating CFRD but insulin should remain the mainstay of treatment until these are further evaluated.