Environmental pollution has become a serious challenge for humanity and the environment. Therefore, this study aims to examine the relationships between the Big Five personality traits, individualism, collectivism, participant's age, and environmental concern, and testing the moderating roles of individualism/collectivism and gender in the relationship between the Big Five personality traits and environmental concern. In this quantitative study, the multi-stage cluster random sampling method was used to recruit a total of 1,160 respondents (614 females and 546 males) from Kuala Lumpur, Malaysia. Structural Equation Modeling proved that respondents of high neuroticism, conscientiousness, extraversion, collectivism, and older ages were conscious of the environmental quality. Also, the findings showed that individualism, collectivism, and gender emerged as significant moderators in the link between the Big Five personality traits and the environmental concern.