Cruciferous vegetables, such as broccoli and watercress, have been studied extensively aiming to evaluate their chemopreventive properties. Some of them have already been established using animal models. The ITCs induce Phase II enzymes related to detoxification processes of chemical carcinogens to prevent the start of carcinogenesis. They also exhibit antitumor activity at post-initiation phase, suggesting their additional role(s) in cancer prevention. Sulforaphane is the most extensively studied isothiocyanate, focused in its anti-tumoral activity and it is mainly found in great amounts in broccoli and other cruciferous. In a dose dependent manner, ITCs inhibit the cell viability of human cervical cancer cells, human pancreatic cancer cells, human hepatocellular carcinoma cells, human ovarian cancer cells, and have antiinflammatory properties in the treatment of human T-cell leukemia cells. This protective effect may be due to improved antioxidant status. Although the health effects of diet in humans are generally considered promising, there are definite challenges and limitations of the current data in better understanding of the molecular mechanisms responsible for this effect, together with the possible interactions between different dietary constituents. The survey of relevant patents on the use of isothiocyanates such as sulforaphane for cancer and cardiovascular diseases treatments is also included in this review.