Nosrat Amin (1886-1983) was one of the most influential female mojtaheda in 20th century Iran, about whom no publication in languages other than Persian exists. This study, by making extensive use of the main Persian-language biographies as well as her works written in Persian and Arabic, sheds light on Amin’s life, her scholarly work, her views on the social relations and her commitments to the public. Moreover, it evaluates the scope of her religious authority before and after her death, and the image that the Islamic Republic has tried to create of this eminent mojtaheda. At the age of 40, Amin was granted the first ejaze-ye rewayat certificate by some prominent ulama (including two grand ayatollahs) and was considered a scholar of the religious sciences. Her gender and her relationship to any of these ulama seem to have been largely irrelevant in these achievements. Whereas Amin could be regarded as an authoritative religious scholar among contemporary ulama during her lifetime, the nature of Amin’s authority in the post-revolutionary era has taken a different shape. It is not her scholarly works as much as her conservative viewpoints on social relations that are emphasized in the Islamic Republic.