Achieving a preventive attitude is the first step in eliminating cancer risk behaviours. This cross-sectional study evaluated the attitude towards the European Code against Cancer, in 3,031 relatives of cancer patients. The study looked for keys to improve attitude by means of educational interventions. Attitude was evaluated using a questionnaire with 63 items and a Likert's scale. Measured from -2 to +2 , the mean score was 0.905 [0.894 - 0.971]. Five per cent had a mean score under 0.38 and another 5% over 1.46. A multivariate analysis found that age, sex and level of education were significantly associated with attitude: young men with a low cultural level were those with the lowest preventive attitude. The family history of cancer was not associated with attitude. Educational interventions should modify the perceived advantages of smoking and drinking, and the disadvantages related to preventive diet and sun and workplace protection.