An increasing body of research suggests that some interventions with offenders can reduce re-offending. While little of this research has focused on the impact of routine supervision of offenders on probation, parole or other community based orders, a few studies have found that when supervisors make use of certain skills those under their supervision offend less often. This study involved the direct observation of 117 worker/client interviews conducted by juvenile justice workers with a view to examining the extent to which effective practice skills were used. It found that workers were strong on relationship and pro-social modelling skills but not as strong on problem solving, role clarification or CBT skills. It found like the earlier studies generally done with adults, that the more workers used effective practice skills the less young people under their supervision re-offended. It also found that workers given a counselling role made more use of the effective practice skills than other workers