This study examined the impact and side effects of a cognitive behavioural program for the treatment of recurrent abdominal pain (R.A.P.) on children's behavioural adjustment and family functioning. It assessed the extent to which changes in children's pain symptoms covaried with family processes thought to be etiologically significant in cases of R.A.P. Results showed that pain symptoms of both experimental and control children improved significantly six months after initial assessment. Treatment achieved its objectives more quickly with a higher proportion of completely pain-free children. None of the measures of child adjustment or family conflict, expressiveness, independence or achievement orientation were associated with changes in pain intensity ratings or parent observational measures of pain behaviour. There was no evidence that treatment was associated with any negative side effects.