The rapid advancement of neuroscience technologies has transformed business and marketing research, yet the evolution of neuromarketing remains theoretically fragmented and methodologically imbalanced. This systematic review synthesizes 395 articles published over the past 2 decades through the lens of theory, context, characteristics, and methodology to examine how key neuromarketing concepts, methodological practices, and research contexts have coevolved. This review identifies 10 major research streams, revealing an evolution from early affect-focused studies of traditional television commercials toward nontelevision and digitally mediated advertising research centered on attention, cognition, and memory, alongside more recent work on communication and product-related themes. However, the field continues to rely on laboratory settings and narrow sampling practices, limiting ecological validity and theoretical generalizability. By integrating theoretical, contextual, conceptual, and methodological components, this review uncovers the systemic interdependencies that have shaped the development of the field. The study concludes by outlining future research directions to advance theoretical refinement, enhance methodological integration, and expand the contextual relevance of neuromarketing research.