Investigations of acoustic cavitation in magnetic liquids subjected to the action of inhomogeneous magnetic fields were carried out for the first time. Possible mechanisms of the effect of the fields on the dynamics of single bubbles, cavitation threshold, and cavitation-induced erosion are considered. The effect of intense ultrasound vibrations on samples of magnetic liquids with a kerosene base are studied experimentally with and without gradient magnetic fields. It is shown that for magnetic liquids prepared with the optimum content of stabilizing substance and subjected to centrifugation in fields of 6·103g the action of powerful oscillations does not affect adversely their performance properties and structure, which supports the use of magnetic liquids as technological media. An increase-induced in cavitation-induced erosion of test samples after application of a gradient magnetic field is revealed.