The halt in fighting promised some relief for Gaza's 2.3 million people, who have endured weeks of brutal Israeli bombardment, and vast killing of nearly 15,000 Palestinians.
The cease-fire kicked off at 7 a.m. local time (0500 GMT) and is to last at least four days.
If it holds, it would mark the first significant break in fighting since Israel declared war on Gaza 49 days ago.
During this period, the resistance group Hamas pledged to free at least 50 of the about 240 captives it and other resistance group took on 7 October and Israel would free 150 Palestinian prisoners of the 8000 detainees it holds.
Both sides will release women and children first.
Israel occupation army said the truce would be extended an extra day for every additional 10 captives freed.
The truce-for-detainees deal was reached in weeks of intense indirect negotiations, with Qatar, Egypt, and the United States serving as mediators.
A first group of 13 women and children held by Hamas will be freed Friday afternoon, according to Majed al-Ansari, the spokesman of the Qatari foreign ministry. Three Palestinian prisoners, also women and minors, are to be released for every freed hostage.
Israel’s Justice Ministry published a list of 300 prisoners eligible to be released, mainly teenagers detained over the past year without trial.
Israeli Prime Minister Benjamin Netanyahu’s office said it notified the families of hostages listed for release Friday.
Increased aid for Palestinians will start to enter Gaza “as soon as possible,” al-Ansari said Thursday. The hope is that the “momentum” from this deal will lead to an “end to this violence,” he told reporters.
Hamas said 200 trucks a day will enter Gaza carrying aid. Qatar said the aid will include fuel, but has given no details on quantities.
Israel cut off all imports at the start of the war, except for a trickle of food, water and medical supplies allowed in from Egypt. The lack of fuel has caused a territory-wide blackout, leaving homes and hospitals reliant on faltering generators.
No end
The agreement raised hopes of eventually winding down the war, which has leveled vast swaths of Gaza, fueled a surge of violence in the occupied West Bank and stirred fears of a wider conflagration across the Middle East.
Israel has pushed back against such speculation, saying it was determined to resume its massive attack for at least "two extra months" once the truce ends.
Israel continued to strike throughout the night ahead of the truce, the occupation army said.
An Egyptian source speaking to Sky News Arabia said that contacts with Israel and Hamas are being made to stabilize the truce agreement and prevent violations after Israel opened fire in the vicinity of the Indonesian hospital.
The Israeli occupation army, which is converting hospitals into military facilities, entered the Indonesian hospital in the morning, killing a wounded woman, and arresting three injured individuals.
The Indonesian hospital, which accommodates over 200 patients and individuals wounded by recent Israeli airstrikes, is now under siege, as indicated by the Palestinian Health Ministry.
In Gaza's largest refugee camp Jabalia, a Palestinian doctor said Israel killed at least 27 people and wounded 93 Thursday in a UN-run school where thousands of displaced civilians were sheltering.
No return for the displaced
The Israeli occupation military dropped leaflets over southern Gaza, warning hundreds of thousands of forcibly displaced Palestinians who sought refuge there not to try to return to their homes in the northern half of the territory. Israel has said it would block attempts to return.
Almost 1.7 million people -- nearly 80 percent of the population -- have been displaced since the war began, according to UN figures.
"The war is not over yet," the leaflets read. "Returning to the north is forbidden and very dangerous!!!"
The Israeli bombardment, now in its seventh week, has killed nearly 15,000 people, 6,150 of them children, according to the Health Ministry, which resumed its detailed count of casualties in Gaza from the war.
The ministry had stopped publishing casualty counts since 11 November, saying it had lost the ability to do so because of the health system’s collapse in the north.
The new numbers were not fully broken down, but women and minors have consistently made up around two-thirds of the dead. The figures do not include updated numbers from hospitals in the north. The ministry says some 6,000 people have been reported missing, feared buried under rubble.
Israel says it has killed thousands of the Palestinians resistance fighters, without presenting evidence for its count.
In Gaza’s city of Khan Younis, Palestinians welcomed the respite of the upcoming cease-fire but said four days would do little to relieve the humanitarian disaster caused by the war.
“God willing, it becomes a total cease-fire,” said Jihan Qanan. “People have had houses brought down on their heads, they’ve been expelled ... There’s no homes, no money, no possessions. The whole world is wrecked.”
For many Palestinian, the truce came too late.
"The last thing he said to me was that he was waiting for the truce on Friday," Fida Zayed, a Gazan whose 20-year-old son Udai was killed in a recent air strike, told AFP.
"The living here are the ones who are dead."
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