Their lawyer, Katib al-Shimmari, alleged on Tuesday all five were also mistreated in Afghanistan and during questioning in the US prison camp on Cuba before their release in May 2003.
The Saudi allegations follow similar charges by British prisoners released from Guantanamo that they were also abused there.
Images of US soldiers brutalising and humiliating Iraqi prisoners at Abu Ghraib prison outside Baghdad have focused new attention on treatment of detainees globally.
US officials have denied any major instances of abuse at Guantanamo, but the only international entity allowed access to prisoners there - the International Red Cross - has said it will inspect the facility and interview detainees there later this month.
The five have never been publicly named, but following their release last year, all five were jailed in Saudi Arabia.
No Saudi official could tell Aljazeera.net why they are being held, or for what reasons.
According to official Saudi estimates, 124 Saudis remain detained in Guantanamo out of about 600 confined there.
Four other Saudis were sent from Guantanamo to Saudi detention last year under a US-Saudi agreement.
Al-Shimmari said he hoped one benefit of the Abu Ghraib scandal could be an improvement of conditions in the Cuba prison camp, possibly even "a legal solution for the fate of the Guantanamo detainees - either by trying them or acquitting them".