Congenital ptosis with poor levator function is now managed by frontalis suspension techniques. While this procedure is better than those used in the past, serious shortcomings exist. A technique producing more normal lid function would be a beneficial addition to surgical management. Since congenital ptosis is thought to be a focal myopathy, we investigated the potential of myoblast transfer therapy in myopathic levator palpebrae superioris. Satellite cells harvested from temporalis muscle were grown as clones, labeled with Dil, and transplanted into experimentally myopathic levator muscle of the same animal. Within 2 weeks, the injected cells were found to be incorporated into muscle fibers within the levator basal lamina. The control side appeared myopathic with very little muscle regeneration. The presence of Dil labeled muscle fibers in the experimental muscles strongly suggests their origin from the injected cells. Electron microscopy of nearby sections showed these fibers to be maturing striated muscle. We feel that the development of this technique may make autogenous myoblast transfer therapy a useful treatment for congenital ptosis and other focal myopathies.