As Sharon spoke on Sunday, several protesters scattered throughout the crowd at Baruch College stood up, with one shouting, "Jews don't expel Jews."
Sharon continued to speak, but the interruption grew louder, and the prime minister had to pause as protesters were escorted out of the Manhattan auditorium.
He then received a warm ovation from the crowd of more than 1000, which overwhelmingly favoured his plan.
"Usually I handle these things myself," he quipped before continuing.
Under Sharon's plan, Israel is to remove all 21 Jewish settlements in Gaza and withdraw from four small settlements in the West Bank.
The plan has divided the Israeli public, with Sharon's opponents accusing him of caving in to Palestinian violence and warning the moves will lead to further territorial concessions.
In his speech, Sharon said the withdrawal would preserve Israel's character as a Jewish democracy and reiterated his stance that the plan will make Israel stronger.
"This plan will improve our security ... it will guarantee a Jewish majority in the state
Israeli Prime Minister
"This plan will improve our security and offer a chance to start a political process with the Palestinians," he said. "It will guarantee a Jewish majority in the state of Israel."
Sharon also said he intends to retain control of large settlement blocs in other parts of the West Bank, ruling out a full return of territory captured and occupied in the 1967 Middle East War and demanded back by the Palestinians.
He said there will be no entry of Palestinian refugees into Israel, rejecting another key Palestinian demand.
"I said in the past, and I say it also today: I am willing to make painful compromises for peace," Sharon said. "I think that the entire world can now see how hard such compromises are.
There is one thing on which we will not make any compromises - not now and not in the future, and that is our security."
Several of the protesters wore orange T-shirts, the colour adopted by Gaza settlers who opposed his plan to remove them from their homes later this summer.
Hundreds of the street demonstrators also donned the orange shirts to underscore their opposition to the Gaza pullout plan, and three of the group ousted from the hall were cheered when they appeared a few minutes later on the outdoor stage.
"We stood up to tell Ariel Sharon to do the right thing," one speaker, David Romanoff, said.
Imposing tight security for Sharon's visit, police barricaded busy East Side sidewalks to effectively prevent any leakage of the protesters, most of them in black orthodox Jewish garb, towards the corner building housing Baruch College.
Chants of "Never again!" and "Let our people stay!" reached a crescendo when Sharon's motorcade passed through the intersection 100 yards away. One woman, opposing the rally, displayed a small Palestinian flag.
The rally featured a parade of rabbis and others voicing specific objections to the planned evacuation of some 9000 residents from Gush Katif, a 30-year-old Jewish community in northern Gaza near the Sinai border.
They described it as a model community that has flourished despite violence and bloodshed.
Settlers are mobilising the public
against Sharon's pullback plan
Speaker after speaker condemned Sharon's withdrawal plan as a sellout of Jewish rights to the land of Israel that offers a hollow promise of peace.
"To retreat in the face of terrorism is to invite more of it - not less," Rabbi Yosef Yitzchok Jacobson, of Brooklyn's Crown Heights neighbourhood, said.
"What have these Jews done to be thrown out? Why are they being expelled? Why not expel the terrorists?"
Sharon arrived in New York for a three-day visit to the US to bolster ties with American Jews, and to discuss domestic issues such as the plan to pull out of the Gaza Strip.
Palestinian leader Mahmoud Abbas "knows what he has to do", Sharon told reporters on his plane. "There certainly has to be complete quiet. Without quiet, it will be impossible to move forward on the peace process."
In recent days, a flare-up of fighting in the Gaza Strip has left three Palestinian fighters dead and resistance groups fired rounds of mortar shells and rockets at Israeli communities.
Chief Palestinian negotiator Saeb Erakat said on Sunday that Palestinians also want hostilities to end so that talks can progress.
"Both sides should exert an effort to achieve full quiet and once the Israeli guns are silent, we can assure that we will maintain the cessation of violence against Israelis anywhere," he said.
Abbas was scheduled to arrive in Washington on Tuesday and meet with President George Bush on Thursday. He has said he would seek political and financial support from the US.
Sharon reiterated that Israel would launch a harsh military response if Israeli troops came under fire during the planned withdrawal from Gaza in the summer. However, senior Israeli officials have said no major military operations in Gaza are planned.
"Once the Israeli guns are silent, we can assure that we will maintain the cessation"
Chief Palestinian negotiator
Under the plan, Israel is to uproot all 21 illegal Jewish settlements in Gaza and withdraw from four small settlements in the West Bank.
Sharon's opponents have accused him of caving in to Palestinian violence and fear the moves will lead to further territorial concessions Sharon dismissed as "baseless" Israeli media reports that the pullback could be delayed beyond mid-August.
Sharon said the forced evacuation of Jewish settlers from Gaza would begin on 16 or 17 August.