She was born in Villa Pianore near Lucca in Italy. Zita married Karl of Austria in 1911 and in the following decade gave birth to eight children, starting with Crown Prince Otto (born 1912), the current head of the Habsburg dynasty.
She was accused by critics of being behind her exiled husband's attempts to regain his throne of Hungary, where the monarchy had been re-established under a regent after the end of the First World War, and from which he had not abdicated. After his death in 1922 she left Madeira but continued living abroad. In old age, from 1962 onward, she lived in Switzerland.
Prior to her death she repeated her conviction that the deaths of Crown Prince Rudolf of Austria and his mistress Baroness Marie Vetsera in 1889 were not a double suicide but murder by French or Austrian agents. Three years after Zita's death, an examination of the remains of Vertsera (which followed its theft, and had been carried out to ensure the returned remains were of the right person) cast serious doubt on the official explanation of the deaths; in particular it was found that she had not been shot as always claimed but battered to death. A subsequent re-examination of files on the deaths also raised serious questions to the matter on Rudolf's death (he too had been involved in a struggle, shot with a gun that was not his and unusually for someone committing suicide managed to fire all six bullets even though the first killed him) and discredited the public 'double suicide' explanation given. With Zita's death however no person remained alive who could supply any information on what the private views of the Imperial family and in particular the private views of Rudolf's father, Emperor Franz Josef of Austria had been on the controversial deaths.
In 1982, the Austrian government granted Zita the right to re-enter Austria although she had never renounced the Habsburg claim to the throne. After her death in Zizers in 1989, she was buried in Vienna's Kapuzinergruft, the crypt in the city centre which had served for centuries as the Habsburg family's burial place, in what was in effect a state funeral, attended by leading politicians, state officials and international representatives from states, including a representative of Pope John Paul II.