He was born of pure Arab stock in Basra and was a pupil there of Abu 'Amr ibn al-`Ala and Khalil ibn Ahmad. He seems to have been a poor man until by the influence of the governor of Basra he was brought to the notice of Harun al-Rashid, who enjoyed his conversation at court and made him tutor of his son. He became wealthy and acquired property in Basra, where he again settled for a time; but he returned later to Baghdad, where he died in 828.
Al-Asma'i was one of the greatest scholars of his age. From his youth he stored up in his memory the sacred words of the Qur'an, the traditions of the Prophet, the verses of the old poets and the stories of the ancient wars of the Arabs. He was also a student of language and a critic. It was as a critic that he was the great rival of Abu 'Ubaida. While the latter followed (or led) the Shu'ubiyah movement and declared for the excellence of all things not Arabian, al-Asma'i was the pious Muslim and avowed supporter of the superiority of the Arabs over all peoples, and of the freedom of their language and literature from all foreign influence. Some of his scholars attained high rank as literary men.
Of Asma'i's many works mentioned in the catalogue known as the Fihrist, only about half a dozen are extant. These include the Book of Distinction, the Book of the Wild Animals, the Book of the Horse, and the Book of the Sheep.