Initiaton of incrustation by crystallization mechanisms is studied. An experimental technique was developed by which nucleation of a crystalline phase on a solid surface is investigated at controlled local supersaturation without the interference of particle deposition. Experiments were carried out with different substances and surface materials. The results show that the solid surface may catalyze primary nucleation and hence promote the initiation of incrustation, but this was recorded only at quite high supersaturation. Collision of crystals with the solid surface in a supersaturated solution may initiate incrustation at a reasonably low supersaturation and can be of substantial industrial importance.