This paper has three goals: 1) to analyze gender differences in subjective psychological well-being, in material well-being, and in personality dimensions such as self-concept, self-esteem, extraversion, neuroticism, and psychoticism; 2) to explore the relationships between psychological well-being and material well-being with personality dimensions; 3) to identify the predictor variables of psychological well-being. The sample comprised 394 participants from 20 to 40 years of age, of whom 183 were male (46.4%) and 211 female (53.6%). The analysis of variance showed differences in neuroticism, with higher scores in the females, and in psychoticism, with higher scores in the males. Pearson coefficients indicate significant and positive coefficients between subjective wellbeing and material well-being. The positive correlations of subjective psychological and material well-being with self-concept, self-esteem, and extraversion are also confirmed, as are the negative correlations with neuroticism and psychoticism. Multiple regression analysis identified the following predictor variables of high psychological well-being: high self-concept, material well-being, self-esteem, extraversion, and low neuroticism.