According to the last estimates about 45,000 people had streamed into Senegal from The Gambia
Political outsider and businessman Adama Barrow won a December election, but for weeks Jammeh refused to recognise the result, setting off a crisis that saw the internationally backed Barrow take his oath of office in Senegal last week.
Jammeh's defiance prompted more than 76,000 people to seek shelter in Senegal, the UN refugee agency said, citing Senegalese authorities.
It said "more than an estimated 8,000 people, as of Monday, have returned to their native Gambia since the political crisis there ended" when Jammeh left the country on Saturday night.
According to the last estimates by the UN High Commissioner for Refugees put out on Friday, about 45,000 people had streamed into Senegal from The Gambia while at least 800 went to nearby Guinea-Bissau since the start of the year.
"Authorities in The Gambia are sending buses to border points to help the displaced return home," UNHCR said, adding that thousands of Senegalese had opened their homes to the fleeing Gambians.
The NGO Enda Tiers-Monde in a statement also hailed "the spontaneous and brotherly mobilisation" in Senegal in the past weeks.