An injection device for setting and injecting a dose of a medicament comprises an elongated housing extending along a longitudinal axis, a piston rod to operably engage with a piston of a cartridge filled with the medicament, a clutch comprising a hollow interior and configured to be rotated in a first direction relative to the housing during setting of a dose and to be rotated in a second direction relative to the housing during delivery of the dosea driver configured to follow a rotational movement of the clutch in the second direction during delivery of the dose, the piston rod being operably engaged with the driver and configured to be displaced along the longitudinal axis relative to the housing when the driver rotates in the second direction, and a retainer configured to prevent a rotational movement of the driver relative to the housing in the first direction during setting of the dose.
