The aim of the study was to describe young families' illness-behavior in connection with minor illness in children aged 0-8 years, and to assess the effect of delivered written health education. The effectiveness of written health education in the management of minor illness was evaluated by a randomized controlled trial. One hundred young families from one group practice were allocated at random to a study group and a control group. The study group received written health education. Health education resulted in more self-treatment and fewer contacts with the general practitioner (GP), and the families indicated worry less often as the main reason for consulting the GP. The GPs' assessment of the appropriateness of the families' consultations showed no significant differences between the study and the control groups. It is recommended that GPs, in connection with prophylactic child examinations, hand over a patient education manual. This manual could form the basis for a dialogue between the GP and the parents when their child becomes ill.