<p>The increase in municipal waste generation by Malaysian households has resulted in an overloading of waste at active landfills, causing them to reach their maximum capacity earlier than expected. In an effort to minimise waste generation, this study attempts to investigate the contributing factors that motivate millennial households in Perak, Malaysia, to practise green disposal and be environmentally conscious. To bridge the knowledge gap, we extend the Theory of Planned Behaviour model by incorporating disposal awareness to explicate millennial households’ green disposal intention. Employing Partial Least Squares Structural Equation Modelling (PLS-SEM), 671 datasets from millennial households in Perak were analysed. The study’s findings indicate that millennials’ intentions (INT) to practise green disposal were significantly influenced by attitude (ATT), subjective norm (SN), perceived behavioural control (PBC), and disposal awareness. We also observed that disposal awareness significantly influences the INT indirectly through ATT. Additionally, this study corroborated the assessment of PBC’s role as a moderator between ATT-INT and SN-INT, which was discovered to have a negative direction with a significant effect. It is found that the moderating effect of PBC has strengthened the relationship of ATT and SN towards INT when PBC is at a low level. Therefore, the study’s overall findings lead us to conclude that millennial households’ intention to practise green disposal is strongly influenced by PBC’s direct impact, the total mediation effect of disposal awareness and ATT on INT. Hence, it has the potential to indirectly divert a substantial amount of municipal waste away from landfills.</p>