Background/Aims: Growth retardation is a recognised complication of paediatric Cushing’s disease (CD), but there are few published data on skeletal maturation at diagnosis. We assessed factors contributing to skeletal maturation in patients with paediatric CD. Patients/Methods: 17 patients, 12 males, 5 females (median age 12.1 years, range 5.8–17.4) were studied. The bone age (BA) of each child was determined by a single observer using the TW3 RUS method. BA delay, i.e. the difference between chronological age (CA) and BA, was compared with clinical and biochemical variables. Results: BA delay was present in 15/17 patients (mean delay 2.0 years, range –0.5 to 4.1 years) and correlated negatively with height SDS (r = –0.70, p < 0.01) and positively with duration of symptoms (r = 0.48, p = 0.05) and CA (r = 0.48, p = 0.05). No relationships were found with midnight cortisol, ACTH, DHEA-S or cortisol suppression during the low-dose dexamethasone suppression test. Conclusions: BA in most children with CD was delayed and related to length of symptoms and height SDS at diagnosis. Early diagnosis will reduce delay in skeletal maturation and thus contribute to optimal catch-up growth.