There are two tendencies in the literature regarding the relationship between income and subjective well-being. The first tendency maintains that there is a strong relationship between these two variables, and that the poorer the population, the more pronounced this relationship. The second tendency downplays this relationship, arguing that a large percentage of happiness cannot be explained by economic variables. The objective of this study was to compare the subjective well-being of three socioeconomic groups -- extremely poor, moderately poor and not poor -- and to discover the combination of subjective well-being factors that makes it possible to predict the socioeconomic group to which subjects belong. Subjective well-being was measured by using an instrument developed by Palomar Lever (2000) and consisting of eleven related factors that inquire into the subjects' satisfaction in eleven areas of life. The results indicate statistically significant differences in nearly all the subjective well-being factors in relation to the socioeconomic group to which subjects belong, with the poorest subjects reporting the least satisfaction. In addition some differences were found in relation to sex and age. Also, low correlations were observed between income and subjective well-being in the extremely poor and moderately poor groups, with more of these correlations in the first group, followed by the last. Finally, it was found that membership in the socioeconomic groups can be predicted by a combination of subjective well-being factors such as satisfaction with one's recreational activities, social surroundings, personal development and couple relationship.