In his autobiography "Tall, Dark and Gruesome" (1977), Christopher Lee identifies this movie as one that was particularly important to him despite the fact that he played a relatively small part. The reasons being were because he was cast against type and because it was the first time he got to act with an American accent.
The Mill Valley police revoked the production's filming permit at the eleventh hour prior to shooting at that location according to an article published in the 1st April 1980 issue of show-business trade-paper 'The Hollywood Reporter'. The American Film Institute's AFI Catalog states that ''the disruption was caused by a local business organization's complaint to City Council that the production would interfere with traffic and parking on a main street in the area. A compromise was negotiated, whereby production trucks were given permission to park at a nearby schoolyard. People and equipment were transported back and forth to sets by bus.''
Harvey (Martin Mull) mentions missing the television show Star Trek (1966). Sally Kellerman, who plays Martha, appeared in the 'Star Trek' episode Where No Man Has Gone Before (1966).
The period of principal photography on this picture was a shoot that ran in 1979 for about three months from the end of May to early September. The picture originally had a thirty-four day shooting schedule according to an article published in the 1st April 1980 edition of show-business trade-paper 'The Hollywood Reporter'.
The name of the cult group was ''The Oriental Church of Christian Harmony''.