In this book we have described in brief about coumarins and antimicrobial activity of some coumarins.The subject can be relevant to any researcher performing research in the field of coumarin chemistry.We have written this book in an easy and understandable way.Through the book we have mentioned various methods for synthesis of coumarins and their spectral properties. Antimicrobial activity of some substituted and fused coumarins have been explained. We have taken utmost care that the book is free of errors.