Many diseases, including caries, chronic inflammatory diseases, diabetes, and obesity, are associated with uncontrolled sugar consumption. Artificial sweeteners are commonly used in food and pharmaceutical industries as sugar substitutes for the prevention of several dental and body diseases; they also have a favorable impact on body weight as they may help to restrict simple sugar consumption. Xylitol is a sugar alcohol that is commonly used as a sweetener. It can be found naturally or artificially prepared mainly from plant materials chemically or by fermentation of hemicelluloses from agricultural biomass by yeast or bacteria strains. This polyol has a significant antiplaque effect on teeth surface and can reduce the gingival inflammation; it is being used as a preventive agent for dental caries due to decreasing the growth levels of pathogenicStreptococcus mutansandStreptococcus sanguiat the very early stages. Xylitol can bind with calcium ion leading to consequent remineralization of teeth enamel; it is also able to prevent osteoporosis. This polyol can treat respiratory tract and middle ear diseases due to its antibacterial and anti-inflammatory potential and prevent some diseases which cannot be cured through antibiotics or surgery. Xylitol can reduce constipation, diabetes, obesity, and other body syndromes or illnesses; it has also revealed its stimulating effect on digestion and immune system. However, it can produce some side effects such as irritable bowel syndrome, diarrhea, nephrolithiasis, etc., when consumed in excessive amounts. Different vehicles are used for delivering the xylitol into the human body, but chewing gums occupy a leading position. The present review is devoted to comprehensive analyses of the positive and negative effects of this polyol on human health. Key Points center dot The health benefits of xylitol are not limited to oral hygiene. center dot Xylitol efficiently stimulates the immune system, digestion, lipid and bone metabolism. center dot Xylitol helps in glycemic and obesity control; reduces ear and respiratory infections. center dot Xylitol treats diseases that cannot be cured through antibiotics or by surgery.