Originally filmed in the late 1960s as a robbery crime-drama, it sat on the shelf for two years before new footage incorporating the zombie plot were shot by investors who wanted a less serious horror flick.
Tommy Kirk admitted in a 1993 Filmfax interview that he was paid $1,000 for two days work. The film was non-SAG and actor Kent Taylor was subsequently kicked out of the SAG for doing non-SAG films for money.