Since energy consumption in developing countries has increased significantly, motivating energy-saving habits among citizens is an important issue both from the academic and industrial perspectives. Thus, this study aims to predict consumer purchase intention for energy-efficient household appliances based on an extended model of the Theory of Planned Behavior (TPB). This study incorporated two additional constructs of moral norms and environmental concern in the model of the TPB. A self-administered questionnaire was distributed to 1155 Bangladeshi consumers, and partial least squares structural equation modeling (PLS-SEM) regression was used to test the hypotheses. Results show that attitude, subjective norms, and perceived behavior control significantly influence consumer purchase intention of energy-efficient appliances (EEAs). This study also proved that the extension of moral norms is a significant predictor of consumers’ purchase intention in the classic theory of planned behavior (TPB). However, environmental concerns had no significant influence in the Bangladesh context. As far as the authors’ knowledge, this is the first empirical survey in Bangladesh to predict energy-efficient household appliance (EEHA) purchasing intentions using an extended model of the TPB. Marketers and policymakers can use the findings of this study to design strategies for generating more value for green consumers. The study also provides insights into environmental marketing and sustainable energy consumption in developing countries from theoretical and practical perspectives.