Mahathir also said the Israelis - whom he described as cruel and arrogant - lied about not having been warned in advance of his visit, Bernama said on Tuesday.
"Jenin is a place where the Israelis caused massive destruction and killed many Palestinians. That's why they prevented me from going there," he was quoted as saying.
Mahathir, a staunch supporter of the Palestinian cause during his 22 years in power, was visiting the West Bank last week when he was prevented from entering Jerusalem and Jenin.
The Israeli authorities, who control the entrance into towns throughout most of the West Bank as well as the border into Jordan, said they had received no advance warning of Mahathir's arrival.
Mahathir said this was a lie as they were notified two weeks ahead of his visit.
"When I arrived there they took more than two hours, comparing my photographs and resorting to all sorts of delay tactics to prevent me from entering so that I will not be able to return from Jenin by 6pm when the border is closed," he said.
"Jenin is a place where the Israelis caused massive destruction and killed many Palestinians. That's why they prevented me from going there"
According to the former Malaysian prime minister, when he changed his plans and said he would go to Jerusalem instead, he received a call saying he could not proceed because of security concerns.
The Israeli government was unavailable for further comment.
Mahathir said the Israelis were cruel because they segregated Palestinian families by erecting a concrete security wall through their villages and seized their land, Bernama reported.
"They are an arrogant lot, they build a 30ft (9.12m) wall not to separate Israel from Palestine ... but Palestinian families, making them travel long distances through checkpoints when they wanted to meet relatives in the same village," he added.
Mahathir, who retired in October 2003, said he visited the West Bank as a show of solidarity with the Palestinians.
The former prime minister caused uproar in Israel just before his retirement by saying that Jews rule the world by proxy, getting others to fight and die for them.