Familial aggregation of blood pressure is well known although its causes remain controversial. The aim of the present study is to evaluate the presence of a familial aggregation for blood pressure and body mass index over a 17-year period, in order to evaluate the importance of a primary prevention strategy beginning in familial environment. Design and methods: A longitudinal cohort study was constructed from two cross-sectional surveys 17 years apart: 1 032 individuals, of both sexes, aged 5 to 24 years were seen in the initial study, and their parents whenever possible. Correlation coefficients and stepwise regression analysis were used to analyse the relationship between parents and children. Results:The correlation between parents' and childrens' BP are : systolic BP-0.34 (p < 0.01) and diastolic BP 0.19 (0.05) : and for the anthropometric variables are: height-0.29 (0.01); weight-0.41 (p < 0.01); ponderal index -0.21 (p < 0.05); tricipt skinfold-0.21 (p < 0.05), All the coefficients are statistically significative. The variance of children's SEP and DBP explained through a stepwise regression analysis was 47 %. The children's weight, skinfold, ponderal index, and parents' SBP and DBP were accepted by the model. Conclusion : The relation between BP and obesity variables suggest that a large proportion of familial aggregation for BP may be explained by aggregation for obesity, still after 17 years.