The invention relates to the lubrication of a planet-carrier for a mechanical reduction gear of a turbine engine, in particular of an aircraft, said planet-carrier comprising a cage defining an internal housing intended to receive a central sun gear with an axis of rotation X, and an annular row of planet gears arranged around the sun gear, said cage comprising two annular walls that are radial with respect to said axis X, and connected to one another at their outer periphery by a cylindrical wall of axis X, at least one of these radial walls comprising orifices for mounting the axes of said planet gears, and the cylindrical wall comprising through-holes for the passage of the gearings of the planet gears so that they may engage with a gearing of the ring gear, which is intended to extend around the planet gears and the cage.