Collins achieved his greatest success in the 1860s. The Woman in White (1859), with its mysterious atmosphere, intricate plotting, and themes of mistaken identity and institutional injustice, became a landmark of Victorian fiction. No Name (1862) and Armadale (1864) further established his reputation for suspenseful, morally complex narratives. His masterpiece, The Moonstone (1868), featuring a stolen Indian diamond and celebrated detectives such as Sergeant Cuff, is often considered the first full-length detective novel in English, profoundly influencing later writers including Arthur Conan Doyle and T. S. Eliot.
Though his later career declined amid health problems and addiction to laudanum, Collins remains admired for his gripping plots, social criticism, and innovative narrative techniques that shaped the modern mystery genre.