• Ablechroiulus anchisporus Andrássy, 1966 accepted as Rhabditis anchispora Andrássy, 1966
• Ablechroiulus dudichi Andrássy, 1970 accepted as Rhabditis dudichi (Andrássy, 1970)
• Ablechroiulus maculosus Andrássy, 1982 accepted as Rhabditis maculosus (Andrássy, 1982)
• Ablechroiulus stercorarius Andrássy, 1987 accepted as Rhabditis stercorarius (Andrássy, 1987)
• Acanthostrongylus acanthostrongylus Travassos, 1937
• Acheilostoma collaris Gogoi, 1985
• Acheilostoma moucheti Railliet, 1918
• Acheilostoma simpsoni Leiper, 1911
• Aelurostrongylus abstrusus (Railliet, 1898)
• Aelurostrongylus falciformis Schlegel, 1933
• Aelurostrongylus pridhami Anderson, 1962
• Aelurostrongylus sinica Wu & Zhang in Wu, Zhang, Hu & Huang, 1985
• Agfa flexilis
• Agfa morandi Ribas & Casanova, 2002
• Agfa tauricus Korol & Spiridonov, 1991
• Agriostomum cursoni Mönnig, 1933
• Agriostomum equidentatum Mönnig, 1929
• Agriostomum gorgonis Le Roux, 1929
• Agriostomum heterochrous Rudolphi, 1802
• Agriostomum vryburgi Railliet, 1902
• Allintoshius baudi Vaucher & Durette-Desset, 1980
• Allintoshius bioccai Rossi & Vaucher, 2002
• Allintoshius nudicaudatus Freitas & Mendonca, 1963
• Allintoshius nycticeius Chitwood, 1937
• Allintoshius parallintoshius Araujo, 1940
• Allintoshius tadaridae Caballero, 1942
• Allintoshius travassosi Chandler, 1938
• Allintoshius urumiac Freitas & Mendonca, 1960
• Alocostoma clelandi (Johnston & Mawson, 1939)
• Alocostoma propinqua Beveridge, 1986
• Amidostomoides acutum Lundahl, 1848
• Amidostomoides auriculatum (Lomakin, 1988)
• Amidostomoides chevreuxi (Seurat, 1918)
• Amidostomoides henryi (Skrjabin, 1915)
• Amidostomoides monodon (Linstow, 1882)
• Amidostomoides orientale (Ryjikov & Pavlov, 1959)
• Amidostomoides petrovi (Shakhtahtinskaja, 1956)
• Amidostomoides quasifulicae (Macko, 1976)
• Amidostomoides tribonyx (Mawson, 1980)
• Amidostomum acutum (Lundahl, 1848)
• Amidostomum anatinum Sugimoto, 1928
• Amidostomum anseris (Zeder, 1800)
• Amidostomum auriculatum Lomakin, 1988 accepted as Amidostomoides auriculatum (Lomakin, 1988)
• Amidostomum biziurae Johnston & Mawson, 1947
• Amidostomum boschadis Petrov & Fedjuschin, 1935
• Amidostomum chevreuxi Seurat, 1918 accepted as Amidostomoides chevreuxi (Seurat, 1918)
• Amidostomum cygni Wehr, 1933
• Amidostomum henryi Skrjabin, 1915 accepted as Amidostomoides henryi (Skrjabin, 1915)
• Amidostomum orientale Ryjikov & Pavlov, 1959 accepted as Amidostomoides orientale (Ryjikov & Pavlov, 1959)
• Amidostomum petrovi Shakhtahtinskaja, 1956 accepted as Amidostomoides petrovi (Shakhtahtinskaja, 1956)
• Amidostomum quasifulicae Macko, 1966 accepted as Quasiamidostomum quasifulicae (Macko, 1966)
• Amidostomum quasifulicae Macko, 1976 accepted as Amidostomoides quasifulicae (Macko, 1976)
• Amidostomum raillieti Skrjabin, 1915 accepted as Quasiamidostomum raillieti (Skrjabin, 1915)
• Amidostomum ryzhikovi Kosupko & Lomakin, 1985 accepted as Mesamidostomum ryzhikovi (Kosupko & Lomakin, 1985)
• Amidostomum skrjabini Boulenger, 1926
• Amidostomum spatulatum Baylis, 1932
• Amidostomum tribonyx Mawson, 1980 accepted as Amidostomoides tribonyx (Mawson, 1980)
• Amira sameera Khalil, 1922 accepted as Khalilia sameera (Khalil, 1922)
• Amira straeleni Schuurmans-Stekhoven, 1943 accepted as Khalilia straeleni (Schuurmans-Stekhoven, 1943)
• Amphibiophilus acanthocirratus Skrjabin, 1916
• Amphibiophilus agamae Sandground, 1929
• Amphibiophilus chabaudi Puylaert, 1967
• Amphibiophilus egerniae Johnston & Mawson, 1947
• Amphibiophilus natalensis Walton, 1935
• Amphibiophilus ranae Wang, 1978
• Amphibiophilus versterae Baker, 1981
• Amphicephaloides thylogale Beveridge, 1979
• Amphidirhabditis longipapillata Andrássy, 1978 accepted as Rhabditis longipapillata (Andrássy, 1978)
• Anafilaroides rostratus Gerichter, 1945
• Ancistronema coronatum Smales, 1992 accepted as Cyclodontostomum purvisi Adams, 1933
• Ancylostoma ascaris
• Ancylostoma bidens Molin, 1861
• Ancylostoma brasiliense de Faria, 1910
• Ancylostoma buckleyi Le Roux & Biocca, 1957
• Ancylostoma caninum Ercolani, 1859
• Ancylostoma canium (Ercolani, 1859) Hall, 1913
• Ancylostoma capri Jetly, 1998
• Ancylostoma duodenale Dubini, 1843
• Ancylostoma galogoi Van den Berghe, 1936
• Ancylostoma genettae Macchioni, 1995
• Ancylostoma gilsoni Gedoelst, 1917
• Ancylostoma guentini Gupta & Kalia, 1984
• Ancylostoma hescheleri Mönnig, 1938
• Ancylostoma iperodontatum Le Roux & Biocca, 1957
• Ancylostoma japonica Fukuda & Katsurada, 1925
• Ancylostoma kusimaense Nagayosi, 1955
• Ancylostoma lucknowense Gupta & Kalia, 1984
• Ancylostoma malayanaum Alessandrini, 1905
• Ancylostoma martinagliai Mönnig, 1931
• Ancylostoma martinezi Miquel, Torres, Casanova & Feliu, 1994
• Ancylostoma memphitis accepted as Ancylostoma mephitis Micheletti, 1929
• Ancylostoma mephitis Micheletti, 1929
• Ancylostoma paraduodenale Biocca, 1951
• Ancylostoma pluridentatum Alessandrini, 1905
• Ancylostoma protelesis Macchioni, 1995
• Ancylostoma somaliense Macchioni, 1995
• Ancylostoma tubaeforme (Zeder, 1800)
• Andersonstrongylus captivensis Webster, 1978
• Andersonstrongylus milksi (Whitlock, 1956)
• Angiostoma asamati Spiridonov, 1985