Quality of life is a multidimensional construct. The study of its determinants in early age groups constitutes a starting point for socio-educational lines of action definition. This study aims to analyse the levels of perceived quality of life in Portuguese children and youth and to compare them according to sociodemographic, anthropometric, family and health variables, in order to understand the consequences for socio-educational practice. 354 Portuguese children and adolescents with a mean age of 12.21 ± 2.92 participated in this ex post facto study. The Portuguese version of KINDL (Ferreira, Almeida, Pisco & Cavalheiro, 2006) was used to evaluate the quality of life and a sociodemographic questionnaire to assess the other variables. The non-parametric analyses were run in SPSS-IBM24, assuming the 95% confidence level. Adequate levels of quality of life were found (92.00±12.23). Encouraging results were found (p≤.05) in the youngest, except in the family subscale; from the coastal area, in self-concept and family;and from rural areas in total. Body mass index and perceived health were, respectively, negatively and positively related (p≤.05) to physical well-being and self-concept. Father's qualifications were associated with self-concept (rho=.15, p =.011). The identification of factors with relevance in the quality of life of children and youngsters will allow the definition of socio-educational intervention guidelines adjusted to the specificities of different groups of the population.