The aim of this study was to identify the most salient characteristics for designing written information for persons with idiopathic scoliosis and their families. A sample of 106 persons with idiopathic scoliosis (n=83) and family members of persons with idiopathic scoliosis (n=23) completed a postal questionnaire to assess perceived level of scoliosis-related knowledge, importance attached to generic design characteristics of information material and preferences for presentation of risk information. Scoliosis knowledge was rated below average for 70% of topics. The most important generic design characteristics were associated primarily with treatment for scoliosis. A majority desired information on benefits/risks of treatment in both absolute and relative terms, and both loss and gain information. Relative frequencies, percentages without decimals, bar graphs, pie charts and Paling Palette were rated as clearest for the presentation of risk information. Respondents lacked knowledge about their condition, which warrants an assessment of current information needs before, during and after treatment, and generic preferences for information and its presentation were identified. Ideally, information material should cover all treatment options including outcome probabilities using frequencies per 100 people and without decimals. Practitioners are best placed to refer persons with idiopathic scoliosis to 'approved' sources of information on the Internet or self-help groups.