Garlic (Allium sativum L.) is considered one of the twenty most important vegetables, with various uses throughout the world, either as raw vegetable for culinary purposes, as also an ingredient in traditional and modern medicine. Further, it has been also proposed as one of the richest sources of total phenolic compounds among the usually consumed vegetables, whereas highly ranked regarding its contribution of phenolic compounds in human diet. This review aims to examine all the aspects related with garlic chemical composition and quality, focusing on bioactive properties of the final produce. A particular emphasis is given on the organosulfur compounds contents, since they exert a great contribution to the effective bioactive properties of garlic,