The letter of recommendation was known in Antiquity as a separate genre of letter writing for which a certain set of compositional techniques and formulae were developed. In Byzantium, too, the letter of recommendation was in great demand: letters in which the author presents his protégé to the addressee and, as a rule, asks him to perform something for him are not difficult to find in the epistolary collections of many authors from the 4th to the 15 th century. Meanwhile, while the ancient letter of recommendation is well studied, the etiquette of this genre in the Byzantine tradition has hardly been investigated yet. The purpose of this piece is to characterize the etiquette norms of Greek letter of recommendation in the early Byzantine period (4th — early 7th centuries). The subject of the study are, first of all, literarische Privatbriefe, belonging to Libanius, Basil the Great, Gregory of Nazianzus, John Chrysostom, Synesius of Cyrene, Theodoret of Cyrrhus, Procopius of Gaza and others, but also private papyrus letters. Their analysis leads to the conclusion that there is a wide variability of the canons of the letter of recommendation, the absence of any rigid scheme that presupposes a clear sequence of structural elements. At the same time, it reveals six recurrent etiquette motifs, all of which are subordinated to a single goal — to persuade the addressee to patronize the recommended person. These motifs are analyzed in detail, and stable formulas are indicated for some of them. An attempt is made to determine to what extent the canons of Greek letters of recommendation of the 4 th–7th centuries go back to the ancient tradition. The letters of recommendation of Cicero and Pliny the Younger, as well as letters preserved on late antique papyri, are used as material for comparative analysis