A process of preparation of autologous fibrin glue for surgical use is disclosed, comprising the steps of taking a sample of blood of the same patient and of concentrating progressively by centrifugation the sample for obtaining a basic product, which when mixed with a starter and other suitable additives produces the fibrin glue ready to be used. A preferred embodiment of the process consists of a closed system using three different plastic bags connected to one another by sealed tubes. More particularly in the first bag the blood sample taken from the patient is collected and mixed with an anticoagulating agent, then separating the plasma from the erythrocytes by centrifugation, said plasma is transferred into the second bag provided with a membrane, where through another centrifugation fibrinogen enriched plasma is separated and transferred to one of the two separated parts forming the third bag, while the other part of the bag contains a thrombin solution, so that by extracting contemporaneously the contents of said two parts and letting them flowing together to a terminal needle, the fibrin glue ready to be used is directly obtained, carrying out a closed system avoiding any contamination of the products.