Consumers do not always follow their ideological beliefs about the need to engage in environmentally friendly consumption. We propose that Commitment to Beliefs —the general tendency to follow one’s value-based beliefs—can help identify who is most likely to follow their environmental ideologies. We predicted that CTB would amplify the effect of beliefs prescribing environmental stewardship, or neglect, on corresponding intentions, behavior, and purchasing decisions. In two studies, CTB amplified the positive and negative effects of relevant EF ideologies on EF purchase (...) decisions, and consumption and conservation attitudes, intentions, as well as future behavior. In each study, only people with higher levels of CTB demonstrated the most ideologically consistent consumption and conservation intentions and behavior. These findings clarify who is most likely to align their decisions and lifestyles according to their sustainable consumption ideologies. The amplification effect of CTB, and the CTB variable itself, present new contributions to consumer behavior research and the domains of sustainable or ethical consumption in particular and offer wide-ranging potential for marketing practitioners and researchers. (shrink)