The suffering, according to AI, stems primarily from the secrecy that shrouds the Saudi criminal justice system, while an oil-dependant international community sits back in silence.
The group is launching a six month worldwide campaign against "arbitrary arrest, torture and executions" in the kingdom coinciding with a report published on Tuesday entitled Saudi Arabia: A Secret State of Suffering.
The suffering, according to AI, stems primarily from the secrecy that shrouds the Saudi criminal justice system, while an oil-dependant international community sits back in silence.
The kingdom - which is the world's biggest oil producer - spent more than $1m in 1999 on public relations firms to ensure secrecy about abuses of human rights.
AI says the state structure in Saudi Arabia is permeated by secrecy and fear. Victims and witnesses are too scared to talk and anyone who dares voice dissent is harshly punished.
"Once trapped in this web, there is only one guaranteed outcome - their basic human rights will be violated."
The most common violations occur against migrant workers, religious minorities and women, the group says.
Saudi rejects report
As in the past, Saudi Arabia rejected Amnesty's report, calling it biased and inaccurate.
"We have nothing to hide in human rights," Prince Turki bin Mohammed, deputy foreign minister responsible for international organisations, told the New York Times.
"There is no harm in having their point of view, but they have to be more accurate in their information," he said.
Amnesty supporters are planning to march between the Saudi Embassy in Washington, the US State Department and public relations firms employed by the Saudi Government and the US State Department.
A week ago the group lobbied the United Nations human rights commission to put aside political and economic considerations and scrutinise the kingdom's human rights record.
Punishments in Saudi Arabia include death by beheading, amputation and flogging, and AI says these can be handed down "after trials that make a mockery of justice".
Highest execution rates
Saudi Arabia is said to have one of the highest rates of execution in the world, averaging two a week, but AI says it provides no information on how victims had been tried.
According to reports the group has compiled over the last two decades, some defendants were tortured into signing a confession, then beheaded.
"Incommunicado detention, a criminal justice system which from the outset treats suspects as guilty, and the lack of independent mechanisms for reporting torture and investigations into allegations, all foster a climate of impunity," it says.
AI says Christians, Sikhs and other minorities are subject to discrimination and are targeted by security forces.
"Political and religious opponents of the government, migrant workers, women and other powerless individuals emerge as consistent victims of discrimination," it added.
Amnesty accuses Saudi Arabia of failing to meet international human rights obligations despite having signed several treaties.
Political groups and trade unions are banned in the kingdom and the authorities do not tolerate any form of public dissent.