The article presents empirical data from a cross-sectional study conducted on a Kazakh sample aimed at assessing psychological well-being. A correlation analysis of the connections between psychological well-being and socio-demographic indicators, as well as indicators of dispositional optimism and the level of self-esteem of ontogenetic reflection was carried out. A close positive correlation of indicators of psychological well-being with dispositional optimism and systemic reflection was revealed. Socio-demographic indicators – the presence of a family and children – showed a close statistically significant positive correlation with psychological well-being. Introspection (tendency to rumination), self-assessment of ontogenetic reflection, as well as quasi-reflection (lack of reflection) have a high negative correlation. There was no statistically significant correlation with the age indicator. As a result of the linear analysis of variance, predictors of psychological well-being were identified: dispositional optimism and systemic reflection, thereby partially confirming the hypothesis about the influence of optimism and reflection on psychological well-being. At the same time, statistics have not been confirmed that age is a predictor of psychological well-being. Age has no correlative and predictive power in relation to indicators of psychological well-being. We believe that in the context of modern world conditions, the study of psychological well-being and its predictors in Kazakhstan has relevance and special meaning.