The invention relates to a plug connector system for a plug connection between electrical conductors, wherein the plug connector system accommodates plug modules with electrical contacts contained therein, wherein said plug modules are first inserted laterally into a region of a holding frame, wherein a plug insert is arranged in the same and locked in place, and then subsequently slid 90° sideways in the holding frame and held in place. The housing frame is designed as a self-supporting part of the plug connector system, for the purpose of accommodating the plug modules, and can provide protection from external influences by means of a surrounding housing.In addition, in contrast to conventional arrangements used to date in plug connectors, the plug modules can be inserted into the holding frames from both sides, meaning in the direction in which the connection is made, or also in the opposite direction, and can be removed again.