Until 1971, Lafferty worked as an electrical engineer. After that, he spent his time writing until around 1980, when his output declined due to a stroke. He stopped writing regularly in 1984. In 1994, he suffered an even more severe stroke. He died 18 March 2002, aged 87 in a nursing home in Broken Arrow, Oklahoma. His collected papers, artifacts, and ephemera were donated to the University of Tulsa's McFarlin Library, Department of Special Collections and University Archives. Other manuscripts are housed in the University of Iowa's Library special collections department.