The state of the art of carbohydrate oxidations with molecular oxygen, hydrogen peroxide and ozone is presented in this review. Catalysed and uncatalysed reactions are described and are related by means of several reaction mechanisms. Several alcohols that are frequently applied as models for carbohydrates are included. Emphasis is given to the selective catalytic reactions. Two summarising reaction schemes conclude the possibilities for oxidations of both reducing and non-reducing sugars.