Al-Ghazali wrote most of his works in Arabic and few in Persian. His most important Persian work is Kīmyāyé Sa'ādat' (The Alchemy of Happiness). It is al-Ghazali's own Persian version of Ihya'ul ulumuddin (The Revival of Religious Sciences) in Arabic, but a shorter work. It is one of the outstanding works of 11th-century-Persian literature. The book was published several times in Tehran by the edition of Hussain Khadev-jam, a renown Iranian scholar. It is translated to English, Arabic, Turkish, Urdu and other languages.

Apart from Kimya, the most celebrated of al-Ghazali's works in Persian is 'Nasīhatul Mulūk (The Counseling Kings), written most probably for Sultan Ahmad Sanjar ibn Malekshah. In the edition published by Jalāluddīn Humāyī, the book consists of two parts of which only the first can reliably be attributed to al-Ghazali. The language and the contents of some passages are similar to the Kimyaye Sa'adat. The second part differs considerably in content and style from the well-known writings of al-Ghazali. It contains the stories of pre-Islamic kings of Persia, especially those of Anoshervān. Nasihatul Muluk was early translated to Arabic under the title al-Tibr al-masbuk fi nasihat al-muluk (The Forged Sword in Counseling Kings).

Zād-e Ākherat (Provision for the hereafter) is an important Persian book of al-Ghazali but gained less scholarly attention. The greater part of it consists of the Persian translation of one of his Arabic books, Bedāyat al-Hedāya (Beginning of Guidance). It contains in addition the same contents as the Kīmyāyé Sa'ādat. The book was most probably written during the last years of his life. Its manuscripts are in Kabul (Library of the Department of Press) and in Leiden.

Pand-nāma (Book of Counsel) is another book of advice and probably attributed to Sultan Sanjar. The introduction to the book relates that Al-Ghazali wrote the book in response to a certain king who had asked him for advice. Ay farzand (O son!) is a short book of counsel that al-Ghazali wrote for one of his students. The book was early translated to Arabic entitled ayyuhal walad. His another Persian work is Hamāqāti ahli ibāhat or Raddi ebāhīyya (Condemnation of antinomians) which is his fatwa in Persian illustrated with Quranic verses and Hadiths.

Faza'ilul al-anam min rasa'ili hujjat al-Islam is the collection of letters in Persian that al-Ghazali wrote in response to the kings, ministers, jurists and some of his friends after he returned to Khorasan. The collection was gathered by one of his grandchildren after his death, under five sections/chapters. The longest letter is the response to objections raised against some of his statements in Mishkat al-Anwar (The Niche of Light) and al-Munqidh min al-dalal (Rescuer from Error). The first letter is the one which al-Ghazali wrote to Sultan Sanjar presenting his excuse for teaching in Nizamiyya of Nishapur; followed by al-Ghazali's speech in the court of Sultan Sanjar. Al-Ghazali makes an impressive speech when he was taken to the king's court in Nishapur in 1106, giving very influential counsels, asking the sultan once again for excusing him from teaching in Nizamiyya. The sultan was so impressed that he ordered al-Ghazali to write down his speech so that it will be sent to all the ulemas of Khorasan and Iraq.