One hundred and fifty letters, written by the great poet Mawlān Jalāl ed-Dīn Mohammad of Balk and later in life of Rūm, who is better known in the West as plain Rumi, have survived and they have been published in numerous editions under the title of Maktūbāt . The author embarks in this paper on a close examination of these letters in an endeavour to highlight their literary merits. The latest edition of these letters, edited by Towfiq H. sobhānī and published by Markaz-e Našr-e Dānešgāhī (Iran University Press) in 1371/1982 has been subjected to the closest scrutiny.These letters make up a diverse lot; some have been addressed to the high personages of Mawlānā's time on behalf of a friend or relative who has been in difficulty, some are amicable missives exchanged with close friends, and a number of them have been written to his sons and daughter-in-law to offer advice. By reading these letters one can have glimpses of life in a 7th/13th century Sufi order in Qūnīyyah (Koniya), but more than that one can see a great literary mind at work, with a supreme mastery of language and vocabulary that enables it to give birth to such an everlasting work as the Masnavī.The author pays close attention to the beginning and ending of the letters, and to the forms of address used, which was a highly specialized routine at the time, citing appropriate examples as he goes along. When a vizier is addressed several lines of titles and prayers precede the body of the letter, and when the letter is written to a friend, just two lines of poetry, in Persian or Arabic, suffice. "The letters of Mawlānā ," writes the author, "are from the beginning to the end a mixture of Persian and Arabic, and so full of allusions to the Holy Qur'ān and the Traditions and the Prayers and to Arabic sayings and poetry that a reader who is not well versed in Arabic and the Koranic lore will not truly appreciate the Maktūbāt."The author underscores all the fine intricacies of Mawlānā's prose in these letters in a systematic fashion and goes on to recommend to universities to make the Maktūbātrequired reading for all graduate and Ph.D. students of Persian literature.