The invention relates to a mounting assembly for mounting a crane (14) on a forest machine (10), the mounting assembly comprising several alternative mounting elements (46), each of them being configured to be mounted between the crane (14) and a mounting point (30) for the crane in the forest machine, and in which mounting assembly - each mounting element (46) comprises a first mounting end (48) for the crane (14) and a second mounting end (50) for the mounting point (30) for the crane in the forest machine； - each mounting element (46) forms the same or primarily the same distance between the crane (14) and the mounting point (30) for the crane in the forest machine； - at least one of the mounting elements comprises a swivel joint in such a way that the first mounting end (48) and the second mounting end (50) of the mounting element are configured to swivel with respect to an axis perpendicular to the longitudinal direction of a part (52) of the mounting element (46) between the mounting ends (48, 50), whereby this axis is primarily parallel to the horizontal plane when the mounting element (46) is mounted in place on the forest machine (10)； and - at least one of the mounting elements comprises a rigid frame (52) between its mounting ends (48, 50). The invention also relates to a forest machine and a method for mounting a crane on a forest machine.
