Priscian was celebrated for the extent and depth of his grammatical knowledge. of which he has left the evidence in his work on the subject, entitled addressed to his friend and patron, the consul Julianus. Other titles are, however, frequently given to it. The first sixteen books treat upon the eight parts of speech recognised by the ancient grammarians, letters, syllables, &c. The last two books are on syntax, and in one MS. are placed as a distinct work, under the title Priscianus made good use of the works of preceding grammarians, but the writers whom he mainly followed were Apollonius Dyscolus (Apollonius, cujus auctoritatem in omnibus sequendam putavi, 14.1, vol. i. p. 581, ed. Krehl) and Herodianus (2.6, vol. i. p. 76, ed. Krehl). The treatise of Priscianus soon became the standard work on Latin grammar, and in the epitome of Rabanus Maurus obtained an extensive circulation. One feature of value about it is the large number of quotations which it contains both from Latin and Greek writers, of whom nothing would otherwise have remained. His acquaintance with Greek as well as Latin enabled him to carry on a parallel between the two languages.

Besides the systematic grammatical work of Priscianus there are still extant the following writings :-- 1. A grammatical catechism on twelve lines of the Aeneid, manifestly intended as a school book.2. A treatise on accents.3. A treatise on the symbols used to denote numbers and weights, and on coins and numbers.4. On the metres of Terence.5. A translation of the Προγυμνάσματα (Praeexercitamenta) of Hermogenes. The translation is however very far from being literal. The Greek original was discovered and published by Heeren in 1791. This and the two preceding pieces are addressed to Symmachus.6. On the declensions of nouns.7. A poem on the emperor Anastasius in 312 hexameters, with a preface in 22 iambic lines.8. A piece , in verse. (Wernsdorf, Poet. Lat. Min. vol. v. p. 212, &100.235, &100.494, &c.) This piece has been attributed by some to the grammarian Rhemnius Fannius Palaemon, by others to one Remus Favinus, but the authorship of Priscianus seems well established.9. An , or De Sideribus, in verse.Wernsdorf l.c. v. pt. i. p. 239.10. A free translation of the Periegesis of Dionysius in 1427 lines, manifestly made for the instruction of youth. It follows the order of the Greek on the whole, but contains many variations from the original. In particular Priscianus has taken pains to substitute for the heathen allusions a phraseology better adapted for Christian times.11. A couple of epigrams. (Anth. Lat. 5.47, 139.) To Priscianus also are usually attributed the acrostichs prefixed to the plays of Plautus, and describing the plot.