A medical-engineering coupling mechanism for connecting two medical instruments having a coupling plug and a coupling socket for inserting the coupling plug, so that the coupling socket and the coupling plug can be secured to one another by at least one spring-loaded notching connection. To produce a medical-engineering coupling mechanism that is easy to manipulate and ensures a secure notching connection of the components that are to be connected to one another, it is proposed with the invention that the notching connection consists of at least two notching hooks that are positioned on one of the components and are in active engagement with at least one spring element configured as a spring washer, and at least one notching recess positioned on the other component for insertion of the at least two notching hooks.