The same court which last month convicted Paolo Gabriele, the Pope's former butler, gave Sciarpelletti a two-month suspended sentence.
Sciarpelletti had been charged with aiding and abetting Gabriele in leaking the document.
But the court decided that he was guilty only of obstruction of justice because he had changed his version of events several times during the investigation.
Gabriele was convicted of aggravated theft at a separate trial last month and sentenced to 18 months in jail for stealing sensitive papal documents and leaking them to the media. He kept some confidential information on his computer.
One of the pope's closest household assistants, Gabriele admitted leaking the documents in what he said was an attempt to help disclose corruption and "evil" in the headquarters of the 1.2 billion-member Roman Catholic faith.
Sciarpelletti spent one night in a Vatican jail cell on May 25, two days after Gabriele was arrested when police searched the former butler's home and found many copies of papal documents, some alleging infighting in the papal court and corruption at the highest levels of the church.
When Vatican police searched Sciarpelletti's desk in the Secretariat of State - the nerve centre of the Holy See's administration - they found a closed envelope addressed to Gabriele marked "personal".
It contained documentation relating to a chapter in a book about Vatican corruption and intrigue written by Italian journalist Gianluigi Nuzzi, who had received confidential documents from Gabriele.
© Thomson Reuters 2012