Introduction. The paper deals with the linguistic data documented in Ph. J. Strahlenberg’s Chuvash wordlist, which is known to be the earliest lexicographic source on the Chuvash language. The wordlist was published in Ph. J. Strahlenberg’s 1730 book but had been, most likely, collected much earlier, in 1711. Goals. The study aims to provide a philological interpretation of Ph. J. Strahlenberg’s wordlist and evaluate its significance for the history of Chuvash. This source has been widely considered to be of little linguistic value and, generally, hardly interpretable because of numerous errors and inconsistencies as well as the brevity of the wordlist. The starting point of this article is the idea that Ph. J. Strahlenberg’s wordlist can still be analyzed if it is taken not as an isolated piece of documentation of Chuvash, but within the broader context of, firstly, Ph. J. Strahlenberg’s materials on other languages of Northern Eurasia and, secondly, other sources on the 18th-century Chuvash language. Materials and methods. It is shown that Ph. J. Strahlenberg has documented 30 Chuvash words in total, including 28 words in the Chuvash wordlist proper, 1 word in the main text of his book, and 1 word mistakenly placed in the wordlist of the neighboring Mari language. These materials have been investigated through standard methods of philological analysis, with a main focus on the orthographic peculiarities of the wordlist (considered against the background of other old written Chuvash sources) and on proposing plausible conjectures. Results. The paper provides a comprehensive philological account of each item on Ph. J. Strahlenberg’s Chuvash wordlist. It is established that almost all difficulties of interpretation that are traditionally associated with this source are rooted in the use of limitedly known orthographic patterns and, additionally, in the distortion of the recorded forms during the period after the original documentation and before the publication of Ph. J. Strahlenberg’s book. After introducing conjectures into the wordlist, it becomes possible to reconstruct phonetic prototypes of the documented forms. This, in turn, sets the stage for placing Ph. J. Strahlenberg’s materials on the dialectological map of Chuvash. While not particularly specific in terms of historical dialectology, the features characteristic of this variety can be broadly described as Viryal Chuvash. Given the extra-linguistic evidence available, it can be assumed that Ph. J. Strahlenberg’s Chuvash wordlist was recorded in the vicinity of Šupaškar (Cheboksary). Therefore, the attested dialect should probably be classified among the northern varieties of Viryal Chuvash.