Besides research on Native American languages and field work on the Modern American English dialects, he is the father of the Indo-Hittite hypothesis, first formulated in 1926, based on his seminal work establishing the Indo-European character of Hittite (and the related Anatolian languages), with Hittite exhibiting more archaic traits than the normally reconstructed forms for Proto-Indo-European.
He authored the first scientifically acceptable Hittite grammar with a chrestomathy and a glossary, formulated the so-called Sturtevant's law (the doubling of consonants representing Proto-Indo-European voiceless stops) and laid the foundations to what later became the Goetze–Wittmann law (the spirantization of palatal stops before u as the focal origin of the centum-satem isogloss). The 1951 revised edition of his grammar (co-authored with E. Adelaide Hahn) is still useful today, although it was superseded in 2008 by Harry A. Hoffner and Craig Melchert's Grammar of the Hittite Language, for which a second edition was published in 2024.
Sturtevant, E. H. (1920, 1940). The Pronunciation of Greek and Latin: The Sounds and Accents. First edition Illinois: The University of Chicago Press, September 1920. Second edition Philadelphia: Linguistic Society of America, University of Pennsylvania, 1940.
Sturtevant, E. H. (March 1926). "On the Position of Hittite among the Indo-European Languages". Language. 2 (1): 25–34. doi:10.2307/408784. JSTOR408784.
Sturtevant, Edgar Howard (June 1931). "Hittite Glossary: Words of Known or Conjectured Meaning, with Sumerian Ideograms and Accadian Words Common in Hittite Texts". Language. 7 (2). Language Monograph No. 9: 3–82. doi:10.2307/522061. JSTOR522061.
Sturtevant, Edgar H. (1932). "The Development of the Stops in Hittite". Journal of the American Oriental Society. 52 (1): 1–12. doi:10.2307/593573. JSTOR593573.
Sturtevant, Edgar H. A. (1933, 1951). A Comparative Grammar of the Hittite Language]. New Haven: Yale University Press. First edition: 1933. Revised edition co-authored with E. Adelaide Hahn: 1951.
Sturtevant, Edgar H.; Bechtel, George (1935). A Hittite Chrestomathy. Philadelphia: Linguistic Society of America, University of Pennsylvania.
Sturtevant, E. H. (April 1940). "Evidence for Voicing in Indo-Hittite γ". Language. 16 (2): 81–87. doi:10.2307/408942. JSTOR408942.