Adams also wrote Dirk Gently's Holistic Detective Agency (1987) and The Long Dark Tea-Time of the Soul (1988), and co-wrote The Meaning of Liff (1983), Last Chance to See (1990), and three stories for the television series Doctor Who. A posthumous collection of his work, including an unfinished novel, was published as The Salmon of Doubt in 2002.
Adams became known as an advocate for environmental and conservation causes, and also as a lover of fast cars, cameras, and the Apple Macintosh. He was a staunch atheist, famously imagining a sentient puddle who wakes up one morning and thinks, "This is an interesting world I find myself in an interesting hole I find myself in fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!"