In their "Japanese Cinema Encyclopedia: The Sex Films" (1998), the Weissers give the film three and a half out of four points. Jasper Sharp comments that the film shows Tanaka's versatility as a director. "Watcher in the Attic" was released theatrically in Japan on June 12, 1976. It was released to home video in VHS format in Japan on September 9, 1994. As part of Geneon's second wave of Nikkatsu "Roman porno" series, it was released on DVD on December 22, 2005. On October 28, 2008, Mondo Macabro released "Watcher in the Attic" in the U.S. on region 0 DVD.