Reports from Vanuatu say Health Minister Willie Reuben Abel was dumped from Cabinet for making critical comments about the government of Sato Kilman.
The government has given no indication why the minister was removed.
While Mr Abel has yet to react to his dismissal, political observers in Port Vila say it could negatively impact on Mr Kilman in the elections later this year.
It is the second time this year that Mr Kilman has sacked a Cabinet Minister.
In January he removed Ralph Regenvanu as Justice Minister for alleged insubordination.
Mr Regenvanu had voted against the government decision for Vanuatu to join the World Trade Organisation.