Shirin studied law at the University of Tehran and passed the judicial qualification exams upon her graduation in 1969, continuing her studies, to earn a Ph.D. in law. As a lawyer, she is known for taking up pro bono cases of dissident figures who have fallen foul of the judiciary.
In 1975 she became the first woman president of the Tehran city court and the first ever woman judge in Iran. However, after the 1979 revolution, pressure from the new regime forced Shirin to accept a demotion to a secretarial position, rather than a judge.
With Western funding, Shirin has founded two non-profit organisations to organise human rights campaigns in Iran. They are the Society for Protecting the Rights of the Child and Defenders of Human Rights Centre. These organisations were instrumental in her winning the Nobel Peace Prize in 2003.
Since 2009, she has lived in exile in the United Kingdom because of increased persecution at home.