Subjective well-being is as important for adolescents as it is in other stages of life. This study thus aims to develop a model for subjective well-being, which is limited to need satisfaction in adolescence and reasons for living, and to test the validity of the model. Participants were a total of 227 individuals, 120 females and 107 males. Data for the study were collected by using the Scale for Basic Need Satisfaction in General, Reasons for Living Inventory, Life Satisfaction Scale and Positive-Negative Affect Scale. The data were analyzed by using the structural equation model. The results showed that, in the model developed, the effects of need satisfaction and reasons for living on subjective well-being were significant and direct; those of reasons for living were significant and indirect; and the total effects of variables were significant. It was thus concluded that the model presented here can be used to increase adolescents' subjective well-being. The results are discussed in light of the literature on subjective well-being and within the context of adolescence as a life stage.