A hair transplant procedure can cover a scar on the scalp very well and in fact, some undergo a hair restoration procedure for the very reason of covering up a scar. For scars on the face, some men opt for a hair restoration procedure to cover the scar with facial hair, for example.
If the scar is very large there would need to be a few adjustments to the technique while performing the procedure. Scar tissue somewhat has a lower blood supply therefore when the hair transplant is performed, the grafts are placed into the perimeter first then they are placed throughout the scar to the outer layer until it is completely covered. Using this technique allows new blood vessels to develop and it also permits additional hair to be added if needed at a later date. If the scar is small, the procedure can be done just as a normal procedure is done. If done correctly, there should be no evidence of a scar.