In a letter to King Abdullah, the rights group described the trial and conviction of Fawza Falih as a miscarriage of justice.
The illiterate woman was detained by religious police in 2005 and allegedly beaten and forced to fingerprint a confession that she could not read.
Among her accusers was a man who alleged she made him impotent.
Human Rights Watch said that Ms Falih had exhausted all her chances of appealing against her death sentence and she could only now be saved if King Abdullah intervened. --BBC
Kings. Witches. Beheadings. 1008 or 2008 -- you be the judge.