The army withdrew from the West Bank settlements of Ganim and Kadim - the first two enclaves to be declared evacuated in August - on Tuesday evening, the military said in a statement.
It pulled out of the nearby settlement of Sanour on Monday and Homesh last week.
On 23 August, Sanour and Homesh became the last enclaves to be evacuated of Jewish settlers under Sharon's pullout plan.
Israeli military sources have stressed that unlike the Gaza Strip, the area evacuated in the northern West Bank will remain under Israeli control, with soldiers continuing to patrol the district.
Lack of coordination
But hundreds of Palestinians swarmed into the evacuated Jewish settlement of Sanour in the northern West Bank on Tuesday, after Israeli troops withdrew without an official handover.
"They left without coordinating with us. We therefore headed to the area with around 100 security service personnel," mayor of Jenin, Qadura Mussa said.
The Palestinians, who arrived in trucks mounted with loudspeakers, sang liberation songs, entered Sanour and three other enclaves in the northern West Bank after Israeli troops withdrew from the settlements earlier on Tuesday.
A ceremony marking the departure of the Israeli troops was to be organised in Sanour later on Tuesday, he added.