Propolis is a resinous substance collected by worker bees (Apis mellifera) from the bark of trees and leaves of plants. This salivary and enzymatic secretions-enriched material is used by bees to cover hive walls to ensure a hospital-clean environment. Propolis extracts have been used both internally and externally for thousands of years as a healing agent in traditional medicine. Its biological properties such as antibacterial, antiviral, antifungal, among other activities, have attracted the researchers' interest. In laboratory tests, studies have shown broad spectrum antimicrobial activity of various propolis extracts and synergism with certain antibiotics has been demonstrated. Although numerous researchers have been reported the biological activities of propolis worldwide, information about Iraqi propolis are still rare. This book provides a new data on the chemical composition and the antimicrobial activity of Iraqi propolis.