Abstract: A biocompatible, bioresorbable and nontoxic adhesive composition for surgical and/or therapeutic use, especially for the bonding of biological tissues to one another or to an implanted biomaterial, is provided which comprises at least one biodegradable macromolecular polyaldehyde of natural origin in aqueous solution and a collagen-based component dissolved in aqueous medium. A process for preparing this composition is also provided wherein these aqueous components are mixed together (e.g., at neutral, physiological pH) to give a gel which is rapidly applied to tissues and/or biomaterial to achieve binding. The present invention is advantageous in that it provides biodegradable macromolecular polyaldehydes with adhesive properties and the ability to be extremely well tolerated by the recipient while retaining their adhesive properties during their retention in the body.