Manish Mishra, formally of Eltham Green school, London, was reprimanded for presenting a false medical certificate to cover his absence.
He claimed in October 2003 that he had undergone tests for a benign tumour in his throat.
King's college hospital, London, where Mr Mishra claimed that he had been treated, failed to unearth any patient records. He resigned on December 4, 2003.
The hearing found him to be of previous good character and a competent teacher.
However, it concluded that he had committed an act of deliberate dishonesty.
Mr Mishra received a conditional registration order. Under this order, he can register again and return to teaching, but must keep the GTC informed about any current or future employment.