Peppard originally signed to star in a weekly hour series, but NBC instead chose to make "Banacek" a 90-minute show that would alternate with two other series on NBC Wednesday Mystery Movie. Peppard's contract was not modified, however, leaving him free to leave the series after two seasons to pursue other projects.
None of the strange, supposedly "Polish" sayings liberally quoted by the lead character is genuine. They were all invented by the script writers with humorous effect in mind. On top of that, "Banacek" is a typical name from Slovakia, not Poland.
When "Banacek" debuted as one-third of the NBC Wednesday Mystery Movie in September 1972, it rotated with "Madigan" (Richard Widmark) and "Cool Million" (James Farentino). During its second and final season, it shared its time-slot with three new shows: "Faraday and Company," "The Snoop Sisters," and "Tenafly." At mid-season 1974, only "Banacek" and "The Snoop Sisters" remained when the show moved to Tuesday.