In this analysis we employed the international Health Behaviour Among School Aged Children (HBSC) 1998 data, comprising 8,326 Irish children and 115,327 children in the international dataset, to examine influences on self-reported health among young people. Factors were similar for both boys and girls and between countries. Daily smokers, those reporting intoxication at least once, those taking infrequent exercise and those reporting difficulty in making friends were all predictive of poor self-rated health in adjusted odds ratio models. Disposable means, as measured by the Family Affluence Score was also a significant predictor of self-rated health but not as influential as reported lifestyle. In a multi-level, between-country comparison of 15 OECD countries, individual health behaviours explained much, but not all, of the variability in poor self-reported health (0.26, SE 0.08) and, of various ecological level indicators considered in the final model, only % voting and % males with minimum 2nd level of male education in the population were influential factors, with between-country variations still not fully explained (0.10, SE 0.03).