We report how the action of radiation forces on small solid particles in a circumstellar disk could induce a suitable mechanism for orbital migration of protoplanets. Since the ratio of radiation-to-gravitational forces acting on a particle depends on its physical and chemical properties, different particles following the same trajectory move with different velocities. Sufficiently large bodies, insensitive to radiation forces, would accrete dust particles that are moving more slowly, thus spiralling towards the central star and transporting mass and angular momentum from the outer to the inner parts of the circumstellar disk. In the case of quasi-circular motion, a simple law relates the masses of the large bodies to their positions. For quantities such as the final mass of the migrating bodies and the time-scale involved, the estimated orders of magnitude resulting from the migration process are well within the cosmogonic scale.