Uri Blau, a reporter with Israel's Haaretz newspaper, was convicted on Tuesday under a plea bargain of possessing classified military documents, an AFP correspondent said.
Blau was convicted at Tel Aviv District Court for possessing secret army papers that he received from a former soldier who was subsequently jailed on charges of spying.
As part of the plea bargain, which was agreed with the State Prosecutor's office on 5 July, Blau agreed to admit to the charge of possessing secret information without intending to harm state security.
Sentencing will not take place until September.
"This is a precedent-setting prosecution of a journalist for doing his job," Jack Hen, one of his legal representatives told the paper's website, saying Blau should not have been indicted and that all of his reports had been approved by the military censor.
"According to it, the public's right to know and freedom of the press were seriously damaged by the decision to put a journalist on trial for these reasons."
Court documents showed that former soldier Anat Kam handed some 1,800 documents to Blau who used some of them as the source for an article in 2008 which said troops had been ordered to carry out targeted killings of Palestinian militants in violation of a Supreme Court order.
Blau later handed over all the classified documents in his possession to the security establishment.
Kam was sentenced to four and a half years in jail in October 2011 after pleading guilty to leaking the documents.
She has said her actions were ideologically motivated and that she wanted to expose the army's policies in the occupied Palestinian territories.