Tai Chi is an internal martial art that develops skill such as natural breathing, structural alignment, mindfulness, imagery, flexibility and relaxation. In the past 50 years, more than 2000 scientific studies and 350 systematic reviews have been published exploring the effects of Tai Chi on health and trying to understand the physiological basis of its effects. In this narrative review, we will expose the multiple benefits of Tai Chi practice on the body, including muscles, bones and articulations, the central nervous system, the cardiovascular and respiratory system, the immune system, correlated to cognition and psychological benefits. We will show that Tai Chi has no described intervention-related serious adverse events. Finally, we will discuss the advantages of Tai Chi practice as a sustainable activity.