The original nationwide judicial system in Iran was implemented and established by Abdolhossein Teymourtash under Reza Shah, with further changes during the second Pahlavi era.

The Head of the Judiciary, also known in English as 'Chief Justice of Iran', is to be a "just Mujtahid" appointed by the Supreme Leader and serve for "a period of five years."

He is responsible for the "establishment of the organizational structure" of the judicial system; "drafting judiciary bills" for Parliament; hiring, firing, promoting, and assigning judges.

Judicial authority is constitutionally vested in the Supreme Court and the four-member High Council of the Judiciary, according to Hunt Janin and Andre Kahlmeyer.

Construction of the new Gohar Dasht prison had been started under the shah, it "was completed with hundreds of solitary cells and large wards housing more than 8,000 inmates".

[16] According to Banakar and Ziaee, the history of the Iranian Bar Association (Kānūn-e Vūkalā-yeh Dādgūstarī) “can be traced back to the period after the 1906 Constitutional Revolution, when a modern legal system was established in Iran.

It operated as an independent civil society organisation for the next twenty-seven years, until it was closed in 1980 by the revolutionary government and its ranks and files were purged.

[17] A new body of lawyers was created by the judiciary in 2001 and authorized to present cases in court under Article 187 of the Law of Third Economic, Social and Cultural Development Plan (adopted in May 2000).

In recent years, Iran has created free trade zones, such as on Kish Island and the port of Chabahar where such rules are not applied in order to stimulate investment, similar to other Muslim countries.

In intentional qisas cases, the sentence would sometimes be delayed for five years in order to increase the chances of a settlement, and allow the criminal to amass the blood money.

One secular critic claimed the Qisas Law of Iran as discriminating against women, non-Muslims, and the poor; as reviving horrific physical punishments; and assuming parts of the human body can be converted into money.

While the victim's/victim's families have a right to retribution (qesas) when the crime is committed intentionally, they are recommended by the Qur'an and judges to forgive the defendant.

In practice, blood money is settled through negotiation between the two parties, and the final sum is usually more or less than the official "100 camels" amounts, unless both sides could not reach a settlement.

[citation needed] In rape/sodomy rape cases, the rapist must pay "jirah", which is similar to blood money, but equivalent to a woman's dowry (mahr), usually in exchange for forgiveness.

[citation needed] Hadd crimes are considered to be "claims against God", and they are punishable by a mandatory, fixed sentence that was laid down in the Koran and Hadith.

[citation needed] These sentences are not commonly implemented (at least in full) due to the high burden of proof and the emphasis on repentance and forgiveness required.

The "vast majority" of offences in the Iranian judiciary system "are related to Ta’zirat crimes," and their rules under Islamic criminal law are more flexible than with Hudud, Qisas and Diyat punishments.

[citation needed] 2) A rapist was forgiven by his rape victim, avoids death but given tazir punishment of 99 lashes, and an additional 8 years in prison.

[citation needed] Civil crimes such as hoolganism (ashrar), aggravated assault (sherarat), rape (tajavoz-be-onf), armed robbery (serghat) receive prison sentences.

[citation needed] If a person commits serious crimes "against the state", such as espionage, treason, activism, "terrorism", and such, they could receive the death penalty for "moharebeh" and "mofsede-fel-arz".

[citation needed] Iran's Anti-Narcotics Law specifies that a person who commits the following drug offenses would be sentenced to death.

Gender dysphoria is officially recognized in Iran today, and the Judiciary permits sexual reassignment surgery for those who can afford it.

[41] On 19 July 2005 two teenagers, Mahmoud Asgari and Ayaz Marhoni, aged 16 and 18, were publicly executed by hanging in Edalat (Justice) Square in the city of Mashhad.

[42] One complaint that critics have of Iran's legal system (and sharia law in general) is that men receive twice as much blood money (diyyeh) as women do.

[citation needed] Human rights activist and Nobel Prize winner Shirin Ebadi complains that the section of the penal code "devoted to blood money, diyyeh, holds that if a man suffers an injury that damages his testicles, he is entitled to compensation equal to a women's life," and this failure to make account for individual differences or cases is unfair.

Ebadi has also protested that while "the Islamic Revolution had anointed the Muslim family the centerpiece of its ideology of nation" and envisions a "restoration of traditional and authentic values" through women playing the role of "Muslim mother" staying home to care for "her multiplying brood," at the same time its family law automatically grants fathers custody "in the event of divorce," and makes "polygamy as convenient as a second mortgage.

In November 2002, Hashem Aghajari, a university professor and veteran of the Iran–Iraq War, was convicted of apostasy and sentenced to death after making a speech telling Iranians not to "blindly follow" clerics.

But after a storm of protests from the general populace, reformist politicians, and human rights advocates, the sentence was later commuted to three years imprisonment, and Aghajari was paroled within months.

Reformist politicians have made attempts in the past to challenge the death penalty, as well as to enforce the rule of law concerning the illegal use of torture in prisons.

Journalists and human rights advocates in Iran who attempt to raise awareness of these issues often risk imprisonment and the death sentence themselves, such as in the case of Akbar Ganji.