Glucosinolates (GLs) are a large group of secondary metabolites which are found in cruciferous plants such as broccoli, cabbage, and kale and contain nutritional and physiological active properties. Several factors affect composition levels of glucosinolates such as storage conditions, methods of consuming vegetables as well as agricultural and environmental factors. When cruciferous vegetables are consumed raw, the myrosinase enzyme found in these plants hydrolyzes the GLs in the proximal gastrointestinal tract to produce a variety of metabolites such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. Myrosinase is inactivated when cruciferous vegetables are cooked before consumption, and GLs transport to the colon, where they are hydrolyzed by the intestinal microbiota. There are many potential health effects of GLs such as antimicrobial, antioxidant, anti-inflammatory and anticarcinogenic activity of GLs. This chapter highlights the natural source of glucosinolates, absorption, the impact of various conditions on their bioavailability as well as their various health benefits.