Iraq is now the world's fourth highest user of the death penalty, human rights group Amnesty International has said.
Saddam's execution was celebrated by many Iraqi political opponents
At least 270 people have been sentenced to death since mid-2004, often after unfair trials the report says, and more than 100 people have been hanged.
Only China, Iran and Pakistan used the death penalty more frequently.
Iraqi officials have dismissed criticism, saying that capital punishment is an intrinsic element of implementing an Islamic criminal code.
One of Iraq's most senior judges, Jafar al-Musawi, said the use of capital punishment was enshrined in the Iraqi constitution. He said that prisoners in Iraq had more rights than in many western countries.
A government spokesman said all executions followed the letter of the law and were carried out with total transparency.
Iraq's US-led occupiers suspended the death penalty after Saddam Hussein was ousted in 2003, but it was reintroduced by the first interim government.
The former Iraqi leader was himself executed by hanging in December.
Amnesty says the reintroduction of the death penalty in Iraq goes against a global trend in which an average of three countries abolish it every year.
Iraq's interim government reintroduced the death penalty in 2004 saying it would act as a deterrent in view of the grave security situation in Iraq.
However, Amnesty International says the extent of violence has increased rather than diminished, and argues that the death penalty may have contributed to the brutalisation of Iraqi society.
Last year, at least 65 people were executed, including two women, the report says.
Amnesty calls for a moratorium on executions in Iraq, and asked that US and British forces do not hand over to the Iraqis any detainees who have been sentenced to death.
"The clock has been turned back in Iraq and we've seen a return to large numbers of people being condemned to death and hastily executed after unfair trials," said Amnesty's UK Director Kate Allen.
The report cites several cases in which defendants were convicted after trials lasting just one or two hours, on the basis of earlier confessions which they had retracted, saying they were the result of torture.
Senior Iraqi judge Jafar al-Musawi criticised the Amnesty International report, saying the death penalty was written into the Iraqi constitution and criminals had more rights in Iraq than in many western countries.
Many of those given death sentences appeared on an Iraqi television show, Terrorism in the Grip of Justice, which was taken off the air in late 2005 after government ruled that televising confessions was illegal.
Many of those appearing on the show bore signs of torture, the report said, and other defendants have alleged that they were tortured before making the confessions.
The report says it was entirely predictable that the restoration of the death penalty would perpetuate and exacerbate the abuse of human rights that was a feature of the former regime.
"Instead of this Saddam-like thirst for vengeance and death, the Iraqi government should be doing its utmost to reinforce respect for life," Kate Allen says.
In addition to the conditions in which executions are carried out, the Amnesty report criticises several aspects of the way the legislation has been enacted.
Safeguards such as the possibility of clemency or pardons are excluded in the Iraqi statute, while people convicted of some non-fatal crimes are given the death penalty.
This violates international law as stipulated by United Nations human rights watchdogs, the Amnesty report says.