Terminated while out on Worker's Comp.

What is the name of your state? Texas

I developed Carpal Tunnel Syndrome & Tendonitis from my workplace and have been on Worker's Comp. seeking treatment (surgeries, therapy, etc.) for these problems since 9/16/04. I have now been fired from my place of employment effective as of August 31st. Can they legally do this?

Yes. Being on Worker's Comp is not a protection against termination. FMLA might have been, but if you have been out of work for a year, the employer has maintained you as an employee FAR longer than they needed to by law. Your termination should not affect your WC case, however.