Unlike its parent series Department S (1969) (shot entirely on 35mm film), this series made use of the cheaper 16mm stock as a cost-cutting move by ITC. This was something of a trade-off, as star Peter Wyngarde was able to be genuinely seen in international location shots interacting with local landmarks. The writing team could then decide how to best integrate this footage in their scripts.
Mindful of how long Peter Wyngarde took in the make-up and hairdressing chair each morning on Department S (1969), the producers simply provided him with a wig to wear on this show.
Jason's publisher Nicola Harvester is played by Anne Sharp. Until his death in 2006 she was the wife for almost fifty years of series producer (and Jason's co-creator) Monty Berman.
The typography on the international end titles background by Chambers + Partners is an example of "Lorem ipsum", the printing and typesetting dummy text standard since the 1500s. The series credits vary slightly but the nonsensical piece usually begins "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum." On the UK original, this is replaced by an image of the author with the dark highlights picked out in the name JASONKING.
Reportedly Peter Wyngarde asked Lew Grade if Joel Fabiani could reprise his Department S (1969) rôle of Stewart Sullivan to partner him in the new series, but the mogul was keener for Jason to have solo adventures.