The aim of this study was to examine an integrated model specifying the antecedents and consequences of youths’ psychological immunity. The model posits that psychological characteristics, family factors, and friend factors influence psychological immunity, which in turn predicts youths’ quality. The sample consisted of 800 undergraduate students in public universities in Bangkok. Self- report inventories with 5 rating scales ranging from always true to never true were administered to collect data. The structural equation model was employed to examine the causal relationship model of psychological immunity. Results using structural equation modeling suggest that the model fits the data. That was, psychological characteristics (self-control, optimism, and locus of control) and family factors (parental relationships, social support from family, and socialization based on sufficiency economy philosophy) positively affected psychological immunity that had impact on youths’ quality in terms of well-beings, problem-solving ability, and prosocial behavior. Specifically, psychological immunity played a mediating role of relationship between psychosocial factors (psychological characteristics and family factors) and youths’ quality. The findings also indicated that the psychological characteristics contributed to psychological immunity the most and family factors were second in terms of strength of its contribution. In conclusions, psychological immunity serves as a protective factor for various threats on individual and also facilitates youths’ quality.