Many of the stories are only loosely based on real events or people, and thus can be considered primarily fiction. Wight's books are only partially autobiographical. He also renamed Donald Sinclair and his brother Brian Sinclair as Siegfried and Tristan Farnon, respectively. In his books, Wight calls the town where he lives and works Darrowby, which he based largely on the towns of Thirsk and Sowerby. The resulting book, titled All Creatures Great and Small, was an overnight success, spawning numerous sequels, movies, and a successful television adaptation. Martin's Press in New York City, received a copy and arranged to have the first two books published as a single volume in the United States. If Only They Could Talk was published in the United Kingdom in 1970 by Michael Joseph Ltd, but sales were slow until Thomas McCormack, of St. Owing in part to professional etiquette which at that time frowned on veterinary surgeons and other professionals from advertising their services, he took a pen name, choosing 'James Herriot'. In 1969 Wight wrote If Only They Could Talk, the first of the now-famous series based on his life working as a vet and his training in the Royal Air Force during the Second World War. Challenged by his wife, in 1966 (at the age of 50), he began writing. Wight intended for years to write a book, but with most of his time consumed by veterinary practice and family, his writing ambition went nowhere. The original practice is now a museum, 'The World of James Herriot'. In January 1940, he took a brief job at a veterinary practice in Sunderland, but moved in July to work in a rural practice based in the town of Thirsk, Yorkshire, close to the Yorkshire Dales and North York Moors, where he was to remain for the rest of his life. In 1939, at the age of 23, he qualified as a veterinary surgeon with Glasgow Veterinary College.

Wight is best known for his semi-autobiographical stories, often referred to collectively as All Creatures Great and Small, a title used in some editions and in film and television adaptations. James Herriot is the pen name of James Alfred Wight, OBE, FRCVS also known as Alf Wight, an English veterinary surgeon and writer.

If only they could talk book