"The prosecution has failed to prove its case against any of the accused. I therefore acquit all the accused," Judge Parkash Lal Ambwani of the National Accountability Bureau (NAB) said in his judgement.
The case relates to some 800 appointments to the national flag carrier, Pakistan International Airlines (PIA), during her second term in office.
Benazir was accused of causing heavy losses to the state by allegedly offering jobs at PIA to supporters of her Pakistan People's Party (PPP).
The case was filed in May 1997 after her arch political rival Nawaz Sharif replaced her as prime minister.
Except for Benazir, who lives in self-imposed exile in London and Dubai, all four co-accused - former MD of PIA AVM Farooq Umer (Retd), PIA Director Ghulam Qadir Shah, political secretary to the then PM Ms Naheed Khan and ex-section officer Najmul Hasan - were present when the judgement was announced. This was the oldest case against Benazir who is still facing about half a dozen other corruption charges, her party officials said.