The OAS suspended Honduras from the grouping after the coup in June
The foreign ministers of six OAS states will arrive on Tuesday and hold talks with the Honduran interim government.
They hope it will accept a plan under which ousted President Manuel Zelaya would return and elections be held.
Mr Zelaya was sent into exile after a coup in June amid a power struggle over his plans for constitutional change.
His critics said the move was aimed at removing the current one-term limit on serving as president, and paving the way for his re-election.
Following the army-led coup on 28 June, the speaker of Congress, Roberto Micheletti - constitutionally second in line to the presidency - was sworn in as interim leader.
The OAS has demanded Mr Zelaya's immediate reinstatement.
It suspended Honduras' membership after the interim government failed to abide by a deadline to restore Mr Zelaya to power.
The OAS delegation will include the foreign ministers of Argentina, Canada, Costa Rica, Jamaica, Mexico and the Dominican Republic. They will be accompanied by Secretary-General Jose Miguel Insulza.
The OAS has demanded Manuel Zelaya's immediate reinstatement
In a statement on Friday, the regional grouping said the delegation was aimed at supporting the "re-establishment of democratic order".
Correspondents say the OAS hopes Mr Micheletti can be persuaded to accept a detailed plan proposed by the Costa Rican President, Oscar Arias.
Under this, Mr Zelaya would return to serve out his presidency and a government of national reconciliation would be set up. There would be an amnesty for political crimes committed during the crisis, and the presidential elections would be brought forward by a month to 28 October.
But the interim government says his return to power is an impossibility. Mr Zelaya says it is "non-negotiable".