WE ARE presenting our experience with the enzymatic agent fibrinolysin in the treatment of several surgical complications. One hundred instances in which the material was used are reviewed in order to evaluate its worth. The proenzyme, profibrinolysin, occurs naturally and circulates in human and animal plasma. The proenzyme becomes activated under certain circumstances during life and also post mortem. It has been shown that an extract of a Streptococcus culture, Lancefield A., possesses an enzyme activator which changes profibrinolysin to active fibrinolysin. This activator is streptokinase, which has itself been used in enzymatic debridement.1Epinephrine and chloroform also have the ability to activate profibrinolysin. As early as 1893 a Frenchman, Dastre,2called attention to the proteolytic activity of the blood serum. Fibrinolysin was first isolated in almost pure form in 1946 by E. C. Loomis and his associates.1aThe material used in this study was obtained from