Nathan Verhelst, 44, died yesterday afternoon after being allowed have his life ended on the grounds of 'unbearable psychological suffering'.
It is understood to be the first time someone in Belgium has chosen euthanasia after a sex-change, and comes soon after it emerged that it is now the cause of nearly one in 50 deaths in the country.
Mr Verhelst died after a lethal injection administered by the same doctor who last year ended the lives of congenitally deaf twins who were also going blind.
Born a girl named Nancy, his transformation into a man began with hormone therapy in 2009, followed by a mastectomy and finally an operation to construct a penis last year.
But the procedures did not go according to plan.
In the hours before his death he told Belgium's Het Laatse Nieuws: 'I was ready to celebrate my new birth. But when I looked in the mirror, I was disgusted with myself.
'My new breasts did not match my expectations and my new penis had symptoms of rejection. I do not want to be... a monster.'
His family learned of his decision this morning via a farewell letter.
Mr Verhelst's decision comes amid a fierce debate over euthanasia in Belgium, where the number of deaths due to the controversial practice soared by 25 per cent last year.'
Official figures showed the numbers opting to end their lives leap from 1,133 in 2011 to 1,432 in 2012, a figure representing about two per cent of all deaths in the country.
Euthanasia is legal under Belgian law if those making the decision can make their wishes clear and are suffering unbearable pain, according to a doctor's judgement.
The Belgian law differs from that of Switzerland, famous for its Dignitas clinic, where only 'assisted suicide' is permitted.
This means patients must play an active role in the administration of the drug that ends their lives.
Wim Distelmans, a cancer specialist who carried out the euthanasia of Mr Verhelst, is the same doctor who last year ended the lives of deaf twins Marc and Eddy Verbessem, who were both going blind.
The 45-year-olds, from the village of Putte, near the city of Mechelen, had lived together their entire adult lives and could not communicate with the outside world.
Their brother, Dirk Verbessem, said at the time that they were terrified of never being able to see each other and feared losing their independence in an institution.
Professor Distelmans agreed to end their lives - again on grounds of 'unbearable psychological suffering' - after their local hospital had denied their request for euthanasia.
Dr Distelmans told the Telegraph: 'The choice of Nathan Verhelst has nothing to do with fatigue of life.
'There are other factors that meant he was in a situation with incurable, unbearable suffering. Unbearable suffering for euthanasia can be both physical and psychological.
'This was a case that clearly met the conditions demanded by the law. Nathan underwent counseling for six months.'
Last week it emerged that a staggering one in 30 deaths in the Netherlands are now from euthanasia, after Dutch government allowed mobile death squads to kill sick and elderly people in their homes.
The country became the first in the world since Nazi Germany to legalise euthanasia when in 2002 it approved doctor-administered lethal drugs for terminally ill people facing unbearable suffering.
Daily Mail