The aim of this study was to investigate differences according to country of birth and parental country of birth, in relation to poor self-rated health (SrH), in Swedish adolescents. Methods: The Scania public health survey among children and adolescents, conducted in 2012, is a cross-sectional study including most pupils in grade 9 (15 years old), including in 32 of 33 municipalities. The participation rate was 83% (9,791 of 11,735). We performed logistic regressions to investigate the association between the students' country of birth, parental country of birth and poor SrH. Results: Boys born outside Europe had an odds ratio (Or) 2.1 (1.6-2.8) of poor SrH in the unadjusted model, which was reduced to 0.7 (0.4-1.3) in the multiple model, as compared to boys born in Sweden with both or one parent born in Sweden. Boys born in Europe had an Or 0.4 (0.2-0.9) of poor SrH, after multiple adjustments. girls born in Sweden with both parents born abroad, and girls born outside of Europe had significantly lower Ors of poor SrH in the multiple model. In particular, adjustment for socio-demographic and psychosocial factors reduced the Ors of poor SrH among boys, but did so to a lesser extent among girls. Conclusions: Differences in socio-demographic and psychosocial factors explained the higher odds of poor SRH among boys born outside of Europe. Girls born in Sweden with both parents born abroad, and girls born outside Europe, had significantly lower ORs of poor SRH. Our results indicate that there are gender differences in the factors behind poor self-rated health, according to the country-related background of adolescents in Sweden.