Agatharchides wrote a few words about his own life. At the conclusion of his book On the Erythraean Sea, he apologizes for being unable to complete his work "since our age is unable to similarly bear the toil" and "as a result of the disturbances in Egypt" he could no longer access the official records (a fragment cited by Photius in his Bibliotheca Cod. 250.110, 460b).
Agatharchides was not well known in ancient times. Of his two major works, Affairs in Asia (Ta kata ten Asian) in ten books, and Affairs in Europe (Ta kata ten Europen) in forty-nine books, only a few fragments survive, too few to provide us with any sense of the contents of either work. However, for his On the Erythraean Sea (Peri tes Erythras Thalasses or De Mari Erythraeo) in five books, almost the entire fifth book, a geographical treatise on the Horn of Africa and the lands around the Red Sea, has survived almost intact. According to Burstein, "the comparative soberness of Agatharchides' treatment compared to previous accounts and the wealth of information contained in it led to a quick recognition . . . [that it was] a valuable summary of the results of Ptolemaic exploration."
In the first book of On the Erythraean Sea was a discussion respecting the origin of the name. In the fifth Agatharchides described the mode of life amongst the Sabaeans in Arabia, and the Ichthyophagi, or fish-eaters, the way in which elephants were caught by the elephant-eaters, and the mode of working the gold mines in the mountains of Egypt, near the Red Sea. His account of the Ichthyophagi and of the mode of working the gold mines, has been copied by Diodorus (iii.12-18). Amongst other extraordinary animals he mentions the camelopard, which was found in the country of the Troglodytae, and the rhinoceros.
- This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "Agatharchides". Dictionary of Greek and Roman Biography and Mythology.
- Burstein, Stanley M., translator and editor. Works Issued by the Hakluyt Society: Agatharchides of Cnidus, On the Erythraean Sea. Second series, no. 172. London: Hakluyt Society, 1989.
- Huntingford, G.W.B., ed. (1980). The Periplus of the Erythraean Sea, by an unknown author: With some Extracts from Agatharkhides 'On the Erythraean Sea'. London: Hakluyt Society. ISBN 978-0-904180-05-3.