The anoretic drug chlorphentermine induces, after long-term feeding, an accumulation of phospholipids mainly stored in lysosomes. Inner hair cells and nerve running to these cells are especially affected, whereas the outer hair cells and their nerves are less changed. Supporting cells and ganglion cells of the spiral ganglion always exhibit inclusions. Changes in the perikarya of the cochlear nucleus are not so outstanding and are in the scope of the alterations found in other parts of the nervous system. The morphological alterations allow some conclusions about the phospholipid metabolism and the lysosomal capacity of the affected cells. Furthermore, experimental lipidosis is considered as an useful model for inherited lipidosis bearing in mind the different pathogenesis underlying both conditions. Last but not least, the clinical consequence has to be pointed out when treating with drugs having different main effects but the same side effects.