Dependence on energy-intense transportation systems could escalate the chances of environmental degradation. A shift of transportation modes from conventional vehicles to energy-efficient vehicles is a viable method of mitigating the rate of carbon emissions; however, the adoption rate of environment-friendly vehicles is still low globally and vital to explore. This study aims to investigate the determinants that influence individuals’ intention to purchase hybrid vehicles, through the development of a research model based on the Theory of Planned Behavior, integrated with environmental knowledge as an additional variable. Data were collected from 256 car users across Malaysia’s metropolitan city. The findings augment the rich theoretical basis of the Theory of Planned Behavior by incorporating environmental knowledge as a supplementary variable in assessing individuals’ behaviour in the sustainable transportation domain, which constitutes the novelty value of this study. The outcomes imply the need for governments and practitioners to execute appropriate approaches in nurturing public’s motivation in adopting energy-efficient cars, so that the adoption rate of pro-environmental vehicles can be increased. Overall, this study infers that the adoption of hybrid vehicles is viable if individuals are properly provided with sufficient awareness and education, which subsequently builds trust, empowerment, and confidence in owning these vehicles.