Can a thesis approved by supervisor fail? What to do to appeal? I am doing PhD in an Australian university.  My thesis was approved by my supervisor, however, one of two examiners suggested revision and re-submission (with harsh criticism and no solid recommendation), and eventually failed it. The committee asked for another examiner and failed it. I would like to know if we can appeal in this situation:


My supervisor has approved the thesis, 
I never had any problem in annual review, and 
I have made revisions in accordance with the comments received from the examiner.
I don't see how you can successful appeal the failure based on your supervisor's approval.  The only recourse is to change supervisor, complain that your supervisor is incompetent, and get the university to waive any penalties to do with late submission.  The supervisor's job is to make sure your thesis is up to the international standard. He/she is not responsible for passing you. In your case, as three external examiners have said no, then there is no way to pass without first doing more work, and then submitting a revised thesis; perhaps sending it to new examiners.  Also, I would definitely get an experienced supervisor or co-supervisor to guide you.   

The other side of the coin is that it is possible that the fault is entirely yours.  I know of students who went ahead with the submission despite having a poor thesis, and the supervisor reluctantly approved the thesis to prove to the student that the thesis is not up to standard.