A board-to-board electrical connector assembly includes a first connector having a dielectric housing for mounting on a first printed circuit board for receiving a plug portion of a second connector mounted on a second printed circuit board. The connectors are mateable in a mating direction. A plurality of first conductive terminals are mounted on the housing of the first connector along the receptacle for engaging a plurality of second conductive terminals mounted along the plug portion of the second connector. A first retention member is mounted on one of the connectors and is engageable with a second retention member on the other connector in the mating direction. The first retention member includes a flexible engaging portion which extends in a direction generally perpendicular to the mating direction. The second retention member includes a rigid engaging portion for engaging and flexing the flexible engaging portion to hold the connectors in mated condition.
