Wellbeing is necessary for a harmonious mental and physical development, from infancy to adulthood and beyond again (Diener & Diener, 2009). It is considered as a multidimensional concept, which integrates -in the specific case of youth- material wellbeing, education, subjective health and personal safety, relationships with family and peers, and risk behaviours (UNICEF, 2007). Wellbeing experienced at school – a context which is not only a place for studying but also a place for living-, is therefore one of the determinants of global Subjective Wellbeing (SWB) of youths. SWB, a central topic of positive psychology, in his most known model has been conceptualized as having three main components: positive affect, negative affect, and life satisfaction (LS) (Diener, 1984). LS is the cognitive component of SWB and it is defined as an individual’s overall appraisal of the quality of her or his life. The aim of the present study, which involved 337 7th grade students, was to analyse relations between personality traits, perceived social support from family and friends, school achievement and subjective assessment of quality of school life (relationships with peers and teachers, safety feeling and climate, boredom and stress emotional states) with LS.