Economic theory holds the assumption that decision making of consumers solely involves rational thought and directly links explicit knowledge with the subsequent behavioural decision. But in recent decades, however, a vast amount of evidence has shown that decision making can be largely driven by psychological factors, based on the notion that the human brain is value-oriented. Recent research in consumer buying has focused on the identification of processes that contribute to an individual making a purchase. Hence the present paper brings out the essential features of neuro science and neuro marketing that emphasis the role brain in stimulating the preferences and decision making. Keywords: Consumer behaviour, Neuro Science, Role of Brain, Neuro Marketing