Written self-disclosure (WSD) has rarely been evaluated as an intervention for paediatric diseases. To test the efficacy of WSD for youths aged 11-18 years with a diagnosis of functional recurrent abdominal pain (RAP), 63 were randomly assigned to receive standard medical care (SMC) alone or WSD in addition to SMC. WSD was administered in three 20-min sessions, one in the clinic and two by phone in the home. Measures of self-reported pain frequency, somatisation severity and quality of life (QOL) were completed at baseline and 3- and 6-month follow-up points. Blind review of electronic medical records provided data on clinic visit and phone consultation utilisation for the 6 months prior to and following baseline. Practice of WSD in addition to SMC was associated with significantly fewer activity-limiting gastrointestinal pain experiences (d = 0.61) and reduced health care utilisation (d = 0.59) 6 months later compared to SMC alone. There were no significant effects for somatisation severity or QOL in 6 months. WSD may be a useful treatment adjunct for reducing pain frequency and resulting health care utilisation in a portion of youths with functional RAP.