Beta-fructofuranosidase is the enzyme which releases terminal non-reducing beta-D-fructofuranoside residues in beta-D-fructofuranosides--saccharides commonly found in plants. Under appropriate conditions this enzyme may also catalyze the reaction of synthesis. Now, beta-fructofuranosidase is one of best biochemically characterized enzymes. Also the 3D structure of this protein has been determined. Resolution of the conformation of beta fructofuranosidase--so far only from a few microorganisms--has allowed for the partial explanation of its substrate specificity and understanding of mechanisms of enzymatic catalysis. This article presents a review of current reports on properties of beta-fructofuranosidases derived from various sources with focus on their structure, mechanism of action, biosynthesis and industrial applications.