Although there are several studies done on the influence of situational, individual and marketing factors on consumer behavior in regard to the amount of commodities bought from retail outlets in the developed world and the emerging markets, there no comprehensive studies that really explains the growth of buying trends in the developing countries like Kenya. This study seeks to investigate what factors are contributing to the new trend of buying from supermarkets and shopping malls in Kenya. The study adopted a survey design on a sample of 1000 consumers in Nairobi, Ruiru, and Kiambu town, and data was collected using structured questionnaires. Regression analysis was used to show the actual effect of consumers' income, ownership of consumer durables (cars and fridges) (marketing factors (prices and exposure to promotion), Socio-psychological factors mainly family size and situational factors (physical environment and antecedent state and temporal situation) on the number of visits to the supermarkets and shopping malls. The results indicated that all the situational factorstime of the day (day time), time of the week, supermarket atmospherics, supermarkets location and antecedent states (excitement) had significant effect on consumer behavior in terms of the number of visits to the supermarkets per month. However, the effect of time of the day (day time) though significant was negative (coeff-.0250, p-value 0.000), an indication that number of times was lower by 0.250 for shoppers doing shopping during the day compared to shopping in the evening. All personal factors except for the age had positive and significant effect on the number of visits to the supermarkets/shopping malls. Perceiving of prices charged by supermarkets as low and exposure to supermarkets existence through advertising and promotions had positive and significant effect on visits to the supermarkets and shopping malls in Kenya. This implied that personal, situational and marketing factors are explaining the new trend of shopping in supermarkets in Kenya. The results also imply that, the investors in large-scale retail business in Kenya have to choose their location carefully away from CBD of the major cities and the pricing strategies have to be well planned because despite the fact that Kenyan consumers are shopping from super markets, they are cash-constrained.