Cyclosporine A is an important immunosuppressant drug that plays an important role in solid organ transplantation. It has also a curative effect in some autoimmune diseases. The present work was designed to study the histological, histomorphometric and ultrastructural changes following administration of cyclosporine A on the kidney of the adult male albino rat, as well as, the possible protective role of vitamin E if used concomitantly or after exposure to cyclosporine A. It was concluded that cyclosporine A caused significant alterations of the renal histological structure, and these alterations were irreversible after withdrawal of cyclosporine A. Concomitant administration of vitamin E with cyclosporine A afforded a partial protection with reduction of the inflammatory reaction.