An autoinjector has a body portion (10, 12) containing a syringe (13) or cartridge with a needle at its forward end, the autoinjector having a drive arrangement (60 . . . ) for effecting operation of the autoinjector and including a drive element that moves from a first position to a second position during the operation, the body including a first (10) and a second body portion (12) connected together by a snap fit arrangement including a resiliently moveable latch finger (138) on one of the body portions that cooperates with a latch surface (142) on the other thereof to hold the two portions connected, wherein the drive element in the second position (60) limits or prevents resilient movement of the moveable latch finger (142), thereby preventing disconnection of the first and second body portions after operation.