Apparatus for filling containers with horticultural products, built and operating in such a manner as to utilize at least one horizontal transporting conveyor, a moving structure arranged at the output edge of said conveyor and provided with displacement and engagement means to incline said containers, through a partial rotation, from a first inclined position with respect to the horizontal plane, in which the mouth of the container remains contiguous with the output edge of the conveyor, and subsequent working positions in which the same container moves progressively through less inclined positions until it returns to the normal horizontal position. Said mobile structure includes a U-shaped oscillating frame whose open side is designed to position itself in front of said output edge of the transporting conveyor, and blocking means, typically shaped jaws, supported by said oscillating frame and suitable to selectively engage and disengage the outer perimeter of the container, so as to initially cause the container to rotate to a predetermined inclination, and subsequently return in reverse rotation to the normal position, in which the container is released and removed.