A team of Spanish surgeons have carried out the world's first double leg transplant.
The operation lasted all night and was completed on Monday morning in the city's La Fe hospital, the regional health authority said in a statement.
"It is the first time in the world that such a transplant has been carried out," it said.
It would not reveal the names of the donors or the patient for reasons of privacy.
But Spain's health ministry announced in November that it planned to carry out a double leg transplant on "a patient who had suffered a trauma above the knee on both legs and for whom prostheses would be no use".
The doctor in charge of the operation, Pedro Cavadas, is known in Spain for having carried out several transplants.
In October 2008 he carried out the first double arm transplant undertaken in Spain and the second in the world, while in August 2009 he performed the first face transplant in Spain.