A dose reset mechanism for a medicament delivery device with a housing and a medicament container includes a dose setting member in the housing for setting a dose when it is rotated and for resetting the dose when it is rotated in the opposite direction. The dose setting member has a drive member connected to a plunger rod such that when the drive member rotates, the rod moves axially and a connection member between the dose setting member and the drive member. A ratchet mechanism enables the connection member to rotate when the dose setting member rotates for setting a dose but not to move in the opposite direction. At least one dose reset member and at least one blocking member are connected to the ratchet mechanism such that the connection member and drive member are released when a dose knob is turned in the opposite direction.