Moi was accompanied by his son Gideon and physician Dr David Silverstein. The former president will be admitted to a hospital in Tel Aviv.
The doctor said they "are eager to have a second opinion on the knee which has been a source of discomfort to him [Moi]."
Baringo Senator Gideon Moi earlier said: "The old man is not feeling well. He will go for medical check-up. So, he needs your prayers as he leaves the country."
While in Israel, Gideon said the 93-year-old former Head of State will visit historical sites in Jerusalem.
The senator revealed his father's trip during a thanksgiving day at Sacho High School in Baringo Central sub-county.
Moi, who will turn 94 on September 2, ruled Kenya for 24 years between 1978 and 2002.
He took over from Kenya's founding father Mzee Jomo Kenyatta following his death on August 22, 1978.
Gideon lauded NASA leader Raila Odinga for the bold move he took to hold talks with President Uhuru Kenyatta on Friday.
"We hope the talks of the two leaders will go along way to bring about peace and prosperity to the people of Kenya," he said.
He said it is important that leaders come together to bring about peace, inclusivity, and economic prosperity to Kenyan people.
"And that will not be possible without engaging one another, we hope this will bring a new beginning to our country," the legislator said.
- The Star