Secretary-General Amr Musa called for "the creation of international commissions, under the auspices of the United Nations, to investigate the predicament of Palestinian prisoners in Israeli prisons and detention centres", according to a statement.
The declaration comes after some of the 8000 Palestinians currently held in Israel began a hunger strike on Sunday in protest against "inhuman prison conditions".
The Arab League statement calls for "measures to be taken to oblige Israel to respect international conventions and to end human-rights violations of which the prisoners are victims".
Musa said Palestinian prisoners were covered by the Geneva Convention on prisoners of war.
The statement called on the international community to help "improve the prisoners' conditions of detention", and denounced what Musa called "the racist declarations of the Israeli interior minister who said that he didn't care what happened to these (hunger-striking) prisoners, even if they die".
The reference was thought to be to Israeli Internal Security Minister Tzahi Hanegbi, who was quoted by state radio on Saturday as saying: "We will concede nothing. From my point of view they can continue their movement to the death."
Meanwhile, Jordan's largest opposition party on Tuesday hailed the "heroism" of the hunger strikers.
The Islamic Action Front (IAF) said in a statement that "international human-rights organisations must assume their responsibilities and defend the rights of these prisoners as guaranteed by international conventions".
For its part, the Jordanian Government called on Israel to respect Palestinian prisoners' rights "in conformity with international law and the Geneva convention", an official spokesman said on Monday.
Arab League wants Palestinian
prisoners' rights to be respected
Some of the prisoner demands include visitation rights of families, which is often either denied or impeded; harassment of visitors and family members; humiliating strip searches in full view of other prisoners and guards; depriving prisoners of medical care.
The complaints list continues with the mixing of political prisoners with criminals and confining children with adults and criminals; solitary confinement, which could be indefinite at times; undue harassment and at times torture by prison guards at gunpoint inside individual cells; and being totally at the mercy of the whims and fancies of Israeli prison guards.
In the wake of the Abu Ghraib scandal, many countries are under pressure to investigate complaints of prisoner abuse.