Drug delivery device has drive assembly adapted to move a piston rod in a distal direction, the drive assembly comprising a drive spring. A rotatable setting member allows a user to set a dose amount to be expelled, the drive spring being strained during dose setting. User actuated release means is provided for releasing the drive spring to thereby move the piston rod in the distal direction corresponding to the set dose. The setting member can be moved axially between an initial position and a proximal setting position, and between the initial position and a distal expelling position, wherein the setting member cannot be rotated to set a dose when in the initial position, the setting member can be rotated to set a dose when in the proximal position, and a strained drive spring is released when the setting member is moved axially from the initial to the distal position.