Journalist Andrew Meldrum, a correspondent for the British Guardian newspaper, was the first person charged under Zimbabwe's tough new media laws.
Mr. Meldrum was accused of publishing a false news story. He had written a report, based on a story published in a local newspaper, the Daily News, that said supporters of Zimbabwe President Robert Mugage had beheaded a woman in front of her children.
Both the Daily News and the Guardian later apologized and retracted the reports.
In finding Mr. Meldrum not guilty, the trial judge, Godfrey Macheyo, said the journalist was not the source of the report and had taken all reasonable steps to verify the facts. He said Mr. Meldrum had published a falsehood, but without intent.
Minutes after the acquittal, an official from Zimbabwe's department of immigration served Mr. Meldrum with an order revoking his permanent residence permit.
The expulsion order had been signed last week. Lawyers representing Mr. Meldrum say this indicates the government had decided, regardless of the outcome of the trial, that he should leave the country.
Mr. Meldrum came to Zimbabwe 22 years ago, shortly after independence, and has been a permanent resident for five years.
Mr. Meldrum said his acquittal means the dozen journalists still facing trial under the media laws, now have a precedent, which had been set in his case.
Human rights and media groups in Zimbabwe hailed the court decision acquitting Mr. Meldrum. But they said his ordered expulsion makes a mockery of the rule of law. The Media Institute of Southern Africa in Harare said the status of all non-government journalists working in Zimbabwe is now in question.