Dextran is a bacterial polysaccharide composed almost exlusively of the monomeric unit a-1,6-glucopyranose linked mainly by a-1,6-bonds. Enzymatic hydrolysis of dextran is carried out with the enzyme dextranase. This paper is a review of world-wide literature concerning properties and production of dextran and dextranase. The important part of the article is the discussion about their significant role and real or potential applications in industry and medicine.