S. T. Joshi is the author of such critical studies as The Weird Tale (Univ. of Texas Press, 1990), H. P. Lovecraft: The Decline of the West (Starmont House, 1990), The Modern Weird Tale (McFarland, 2001), and Unutterable Horror: A History of Supernatural Fiction (PS Publishing, 2012). He has edited a corrected edition of H. P. Lovecraft’s fiction (Collected Fiction: A Variorum Edition [Hippocampus Press, 2015–16]) as well as The Ancient Track: Complete Poetical Works (Night Shade Books, 2001; rev. ed. Hippocampus Press, 2013) and Collected Essays (Hippocampus Press, 2004–06; 5 vols.). He has prepared three annotated editions of Lovecraft’s tales for Penguin (1999–2004). His exhaustive biography, H. P. Lovecraft: A Life (Necronomicon Press, 1996), won the British Fantasy Award and the Bram Stoker Award; a revised and expanded edition has appeared as I Am Providence: The Life and Times of H. P. Lovecraft (Hippocampus Press, 2010).

Joshi has done scholarly work on other authors of supernatural fiction. He is the author of a bibliography (Scarecrow Press, 1993) and critical study of Lord Dunsany (Lord Dunsany: Master of the Anglo-Irish Imagination [Greenwood Press, 1995]), and a critical study of Ramsey Campbell (Ramsey Campbell and Modern Horror Fiction [Liverpool Univ. Press, 2001]). He has prepared editions of the work of Arthur Machen, Algernon Blackwood, Lord Dunsany, M. R. James, Ambrose Bierce, and other writers. He is the coeditor (with Stefan Dziemianowicz) of Supernatural Literature of the World: An Encyclopedia (Greenwood Press, 2005).

Joshi has edited such anthologies as American Supernatural Tales (Penguin, 2007), the Black Wings series (PS Publishing, 2010f.), Searchers After Horror (Fedogan & Bremer, 2014), A Mountain Walked: Great Tales of the Cthulhu Mythos (Centipede Press, 2014), and The Madness of Cthulhu (Titan Books, 2014–15).