An organization devoted to defending Palestinian Arabs said yesterday it will ask President Carter to appoint a "commission of inquiry" to examine charges of mistreatment of Palestinian prisoners by Israeli authorities on the West Bank of the Jordan River.

The Palestine Human Rights Campaign, a Washington-based group, said its request was prompted by a recent report from Amnesty International, the State Department's 1979 human rights report, and a story in Wednesday's Washington Post, all of which indicated that Israeli authorities have mistreated Palestinians in interrogation centers on the West Bank.

Dr. James Zogby, a professor of religion at Shippensburg (Pa.) State College, who heads the organization, said the group will ask for a commission to determine whether physical abuse of prisoners is a systematic practice at interrogation centers in the Palestinian territory occupied by Israeli military forces.

The government of Israel, while conceding that physical abuse has occurred, says that such instances are aberrations which violate official policy.

Zogby, speaking at a press conference here, said his group's call for a formal U.S. inquiry has been endorsed by civil rights leader Rev. Ralph David Abernathy, journalist I.F. Stone, and Princeton University political scientist Richard Falk.