The level of life satisfaction perceived during childhood and adolescence is an excellent indicator of healthy psychological emotional development. The main aim of this work is to study the levels of life satisfaction perceived by young people throughout their childhood and adolescence. To this end, an innovative retrospective approach is adopted that shows how the evolution of life satisfaction is perceived at different ages according to gender. The present study is based on a sample of 600 Spanish adolescents (58.1% girls; mean age = 16.64) who report the evolution of their life satisfaction from 6 years to 18, through the Life Satisfaction Chart (LSCh). The Goldberg Anxiety and Depression Scale (GADS) is also administered to record levels of anxiety and depression. The results indicate no gender differences in terms of life satisfaction during childhood. Levels of life satisfaction are significantly higher in childhood than in pre-adolescence and adolescence and a significant decrease in levels appearing towards the age of 11. As for gender, significant differences in life satisfaction appear from the age of 12, with girls being significantly more dissatisfied, more depressed and more anxious than boys. Current levels of anxiety and depression do not appear to interfere with retrospectively reported levels of life satisfaction throughout the developmental years studied, except among the female population, where minimal interference is detected. Life satisfaction retrospectively reported by young people shows a significant decrease after the age of 11 years, with greater emotional and psychological vulnerability after this age, mainly and notably among girls. The present results highlight the importance of psychological/affective care in the pre-adolescent and adolescent stages, especially among the female population.