We report our experience on myoblast transplantation in three Duchenne muscular dystrophy patients. Pure myoblasts (55 x 10(6) per patient) from HLA-matched donors, were injected into a tibialis anterior and the controlateral muscle was sham injected. Three months after transplantation, biopsies from the injected muscles were negative for dystrophin expression by immunocytochemistry. Reverse transcriptase-PCR (RT-PCR) failed to amplify any fragments of the deleted regions. This result confirms that myoblast transplantation is feasible, although the efficacy of this therapeutic approach is poor.