This book focuses on the in vitro studies on the antimicrobial activity in stems of Montrichardia arborescens (Moco moco) and combined extract of Montrichardia arborescens stems and Azadirachta indica (Neem) leaves with the view to promote continual development of natural antibiotics, in light of the fact that microorganisms develop resistance to antimicrobials as a result of indiscriminate use of synthetic antimicrobials. Antimicrobial resistance will continue to plague mankind and there is an urgent need to find alternative antimicrobials. In addition, synthetic antimicrobials when administered usually produced adverse effects which are usually irreversible when and the cost of synthesising drugs is an expensive endeavour. Natural antimicrobials from plants continue to offer a lot of scope in this context. Little or no research has been reported on the antimicrobial activity of Montricardia arborescens, a plant endemic to the Guyana's flora. No research findings prior to ours has reported the antimicrobial activity of combined extracts from both plants.