Abstract Introduction The cystic fibrosis-related diabetes (CFRD) guidelines produced by the UK CF Trust differ from those used in Europe and the US. We conducted a study to establish current practice. Method Paediatric and adult questionnaires were devised and emailed to the 48 specialist UK CF centres. Results Completed questionnaires were returned by 39/48 (81%) centres. Only 3/21 (14%) paediatric centres begin annual screening at 12years (as per UK guidelines), 11/21 (52%) start to screen at 10years (as per European and US guidelines) and 5/21 (24%) begin screening at a child's first annual review. The oral glucose tolerance test is used as a screening test in 33/39 (85%) of centres but only 3/33 (9%) use it in isolation. Home glucose monitoring is the most frequently used diagnostic test undertaken in 32/39 (82%) centres, and again this is rarely used in isolation. The decision to initiate insulin is often shared between specialist nurses and doctors. Conclusions In the UK the majority of CF centres use the OGTT to screen and HGM to diagnose CFRD. The use of other tools varies with poor adherence to UK guidelines. These 2004 guidelines would benefit from being updated to reflect current best evidence.