In the works generally accepted as authentic, ʿAttar reveals almost nothing directly about himself or his circumstances: he mentions no travels, legal affiliation or spiritual guide; he names only one contemporary and no disciples, patrons or historical addressees. Likewise, the earliest external accounts of the poet – from ʿOwfi (d. 1232) and Nasir al-Din Tusi (d. 1274) – are exceedingly terse and do not fill many of these gaps. Later biographical sources such as those of Jami (d. 1492) and Dowlat-Shah (d. c. 1507) are much more extensive, but they were written more than 200 years after ʿAttar's death and motivated by a hagiographical agenda. They narrate his life according to the expected contours of saintly vitae, complete with sudden conversion, extravagant martyrdom and continuing spiritual presence in the world after death.

More than any other aspect of his biography, the lack of information on ʿAttar's spiritual training – and thus his status as a ‘true’ sufi – has generated much scholarly handwringing. According to the idealised portrayals of the sufi manuals, an aspiring sufi ought to enter into formal discipleship with a shaykh who, after a period of training and service, will invest the novice with a sufi cloak (kherqa) signifying their admission into the sufi community. ʿAttar, however, makes no mention of a formal spiritual guide in his undisputed works, and neither do the early accounts of his life. Eager to solve the mystery, scholars from the Timurid period onwards have suggested a number of potential guides, ranging from the chronologically plausible (Majd al-Din Baghdadi [d. c. 1209]) to the paradoxically fantastic (Shaykh Sanʿan!). On closer inspection, however, even the more plausible suggestions have proven unfounded. Given the ambiguity over his organisational affiliation, several scholars have concluded that ʿAttar cannot properly be called a sufi at all. Ritter, for example, writes that ‘ʿAṭṭār was a pharmacist and doctor, and whilst not actually a Ṣūfī, he admired the holy men and was edified by the tales told about them, from his youth onward’. Rypka, echoing Ritter, writes that ʿAttar was not a ‘true sufi’, while Kermani describes him as ‘more of an empathetic observer of Sufism than an active exponent’, who ‘consciously kept his distance from the Sufi scene’.