This study evaluates the impact of therapeutic preparation methods on children undergoing MCUG. Parents of 35 children who had undergone MCUG were surveyed by questionnaire. The child's reaction to investigation was assessed using the Groningen Distress Rating Scale (rating 1 = calm > 5 = panic) and parental coping styles using the Utrecht Coping List. Families received one of two types of therapeutic preparation: storybooklet or storybooklet and play preparation. Reported distress levels were significantly lower with therapeutic preparation (mean score 2.5 +/- 1.02 SD) than without (mean score 3.3 +/- 1.22 SD). Previously, controls reported 46% of anxiety-linked behaviour changes post-MCUG, falling to 13% after therapeutic preparation. Parents who gave a candid explanation reported significantly lower child distress levels (mean 2.0 +/- 0.91 SD) than those parents who avoided upsetting details (mean 3.1 +/- 0.47 SD). We conclude that distress associated with the MCUG can be reduced by therapeutic preparation of the child and family prior to investigation.