Generation Z has emerged as a demographically significant and ideologically distinctive consumer cohort whose environmental consciousness coincides with growing purchasing power in emerging-market economies, yet the translation of this environmental consciousness into actual green purchase behavior remains empirically inconsistent and theoretically contested. This paper reviews the consumer-behavior literature on Generation Z green purchase decisions in emerging markets, synthesizing Theory of Planned Behavior (TPB) applications across China, India, and Vietnam with the value-belief-norm and value-attitude-behavior frameworks that extend TPB's explanatory power, and with the greenwashing-perception and attitude-behavior-gap literature that explains why favourable environmental attitudes so often fail to convert into purchase behavior. Particular attention is given to the specific psychological and contextual factors, perceived green quality, environmental concern, subjective norms, perceived behavioral control, price sensitivity, and greenwashing scepticism, that the reviewed studies identify as significant, non-significant, or context-dependent predictors of green purchase intention among Gen Z consumers specifically. Comparative tables map TPB and extended-TPB constructs to their reported significance across studies and national contexts, cross-reference documented barriers to the attitude-behavior gap against the marketing and policy responses the literature proposes, and set Generation Z's distinctive green-consumption profile against that of preceding generational cohorts. The review finds that while attitude, perceived behavioral control, and green perceived quality function as consistently significant predictors across emerging-market contexts, subjective norm's influence is highly context-dependent, and greenwashing perception has emerged as an increasingly dominant negative moderator capable of substantially undermining otherwise favourable pro-environmental purchase intentions....