The invention relates to a fin deployment mechanism (1) comprising a base unit (3), deployable fins (8) movably arranged on the base unit (3) and, in the retracted position, bearing against the base unit (3), as well as a gas-generating device, in which the fins in the retracted position are fixed to the base unit, and in which at least one gas duct (6, 7) is arranged in the base unit (3) so as to conduct pressurized gas generated by the gas-generating device to the bottom side of the fins (8), which in the retracted position bear against the base unit (3), in order to create a force which acts on the fins (8) for deployment of the same (8′). The invention further relates to an artillery projectile comprising a fin deployment mechanism.