Before turning to novels, Parker combined his interest with hardboiled detective fiction with his academic career. His PhD thesis included material on Dashiell Hammett, Raymond Chandler and others. Parker was teaching at Northeastern University when the first Spenser book saw publication and continued in that position until 1979. More recent Parker creations include the Jesse Stone and Sunny Randall series. He also wrote westerns, non-fiction, and two novels featuring Chandler's Phillip Marlowe, one of them a completion of Chandler's unfinished Poodle Springs.
Asked by bookreporter.com in 2000 if he had written a final Spenser adventure to be published after his death, Parker replied, "Oh no! That's not fair to the reader at all. Spenser will live forever, at least as long as people want to remember him, and me. And I don't want to work hard on a book that is not going to be published in my lifetime. I want the money now! And, of course, I want to see the book published."