Caffeine is a chemical compound belonging to the class methylxanthines which acts as stimulant. It is a widely consumed stimulant which helps to prevent drowziness and enhances alertness by its action on the central nervous system. The effect of caffeine is well known among humans and it is commonly consumed in the form of coffee. Coffee beans have a bitter taste which acts a as a deterrent against certain animals and insects. However, in this study we will discuss about the effect of caffeine on growth of bacteria isolated from Vellore. Caffeine can be extracted from various sources like coffee beans, tea, Cacao beans, Kola nut etc. In our study, we have extracted caffeine from commercially available coffee powder and bacteria from soil. Then, by using spread plate technique, we cultivated the bacteria to observe its growth in the presence and the absence of caffeine [7,10]. We also used various stains to observe its morphological changes. © 2018, Research Journal of Pharmacy and Technology. All rights reserved.