It is advising citizens to avoid non-essential travel
The Department of Foreign Affairs say they are making contact with Irish people registered with it in Gambia.
It is advising citizens to avoid non-essential travel to the African nation due to growing political unrest.
In a statement, the department says: "Since the presidential elections in December 2016, there is an ongoing political and security crisis in the Gambia.
"It is possible that there will be external military intervention and further civil unrest. Irish citizens in the Gambia should carefully consider their need to remain in the country.
"Because there is no Irish embassy or consulate in Gambia, we're limited in the help we can offer you in an emergency. The best help is often close at hand so if you have problems, try talking to your local contacts, tour operator representative or hotel management," it adds.
In an emergency, citizens can contact the Irish embassy in Abuja, Nigeria on +234-9-462-0611 - or the Consular Assistance Unit at the Department of Foreign Affairs in Dublin on +353-1-408-2000.
It comes as Gambian President Yahya Jammeh declared a state of emergency, after refusing to hand power to opposition leader Adama Barrow, who won last month's election.
Mr Jammeh has ruled Gambia for 22 years since seizing power in a coup in 1994.
He initially acknowledged Mr Barrow as the winner but later said the ballot count was flawed and lodged a complaint with the country's Supreme Court.
State television said the state of emergency would prevent a power vacuum while the court rules on Mr Jammeh's petition challenging the election result.
While neighbouring coutries say they are ready to take action, if neccessary.
Senegal says troops will take action at midnight, unless a solution is found to the crisis.
"We are ready and are awaiting the deadline at midnight. If no political solution is found, we will step in," said Colonel Abdou Ndiaye, a Senegalese army spokesman.
The Nigerian air force is also ramping up the pressure.
It has deployed fighter jets and surveillance planes to Senegal, which borders Gambia.
It says it has moved "200 men and air assets comprising fighter jets, transport aircraft, light utility helicopter as well as intelligence, surveillance and reconnaissance aircraft" to Dakar in Senegal.
Ghana has also pledged to contribute to the regional force.
Thousands of UK holidaymakers are also being flown home to Britain.
Holiday company Thomas Cook is laying on additional flights from the capital Banjul to bring 985 package trip customers home.
It also said a flight scheduled from Manchester will leave the UK without passengers and bring the first group of tourists home.
A further four flights have been arranged from Banjul back to the UK.
Additional reporting: IRN