A system (10) for combined vacuum and instillation treatment of wounds on the human or animal body. The system (10) has a vacuum unit (14) with a housing (18) of a first housing type and an instillation unit (30, 30a, 30b) with a housing (34, 34a 34b) of a second housing type. The housing (34, 34a, 34b) of the second housing type has an openable and closable cover (46, 46a, 46b) through which a conduit passage area (42) is accessible. The housing (18) of the first housing type has a first securing mechanism (50) which can be connected to a second securing mechanism (52, 52a, 52b) of the housing (34, 34a, 34b) of the second housing type with a form fit, a snap fit, a latching fit, a fit engaging behind with a form fit or with a clamping fit.