Plants play a vital role in the life of every living being. The global inclination towards herbal medicine has advanced the expansion of plant-based pharmaceutical industries to a vast extent. Plants are rich in both primary as well as secondary metabolites collectively called as phytochemicals. Today, these phytochemicals in medicinal plants have received an immense importance due to their role in preventing diseases caused by oxidative stress which releases reactive oxygen species. The genus Syzygium is one of the genera of the family Myrtaceae that is native to the tropics which plays an important medicinal role all over the world. The species of the Syzygium possesses various pharmacological properties including, antioxidant, hypoglycaemic, antimicrobial, anti-inflammatory, anticancer and hepatoprotective activity. All the pharmacological properties are due to the presence of flavonol glycosides, jambolin, eugenol, quercetin, myricetin etc., This book highlights the review of ethno phyto pharmacological uses of Syzygium sps., worldwide. We hope that this book would be of great use to under graduates, postgraduates, researchers and faculty members who are studying, teaching or working in the field of Life science, Phytochemistry and Ethnopharmacology. This book could be of immense use for the researchers working in this area. I shall deeply appreciate receiving any critical comments and suggestions from the readers which would help me to improve further publications.