The film came in two million dollars below its budget. Co-producer Rhonda Tollefson credits this to Producer Sean Connery's thrifty Scottish ways. Connery drove his own car, instead of hiring a driver, and flew on commercial planes, instead of using private ones, so that all of the money, would show up onscreen.
Ronald Bass' original screenplay contained numerous additional spectacular action sequences involving Mac, including a robbery taking place onboard a moving luxury train, but 20th Century Fox balked, when the initial budget for this script was estimated at over 130 million dollars. The final film excised many of Bass' envisioned super-action scenes (keeping a handful for the theatrical release) and came in at a final budget of seventy million dollars.
In the original script, the climactic events were set to take place the minute that Hong Kong reverted back to Chinese rule. However, director Jon Amiel preferred to use something more timely, so the Millennium Eve became the catalyst event.
While Antoine Fuqua was briefly attached to direct, he wanted to increase the action sequences. Fuqua envisioned a rather large, epic scale car chase for the scene where Gin and Mac escape from the shady antiques dealer, and the climactic heist was to feature more high-tech gadgets and a much more intricate escape. Sean Connery was not happy about Fuqua's plans for the film, in fact, in a 1999 issue of Premiere magazine, he said that Fuqua tried to turn the film into "The Rock", which Connery believed wouldn't have worked for the picture.
Malaysia objected to the depiction of their country as a backwards one when a shantytown in Malacca was superimposed over a tilt shot of the Petronas Towers. In reality, Malacca is nowhere near the Towers.
In the opening sequence, the passcode on the security unit that the thief uses is 1007 for Sean Connery as he was the first cinema 007. In truth, Barry Nelson was the original James Bond. He played the part on U.S. television, playing CIA Agent James Bond in Climax! (1954) (Casino Royale (#1.3)).
Catherine Zeta-Jones and Maury Chaykin previously starred in The Mask of Zorro (1998), and in that film, the main protagonist Alejandro Murrieta (Antonio Banderas) is a thief, who becomes the masked hero, Zorro. Also, Catherine Zeta-Jones played Elena, and Maury Chaykin had a small role as a prison warden.
Some of the information in Mac's file includes D.O.B. (August 21, 1937); P.O.B. (Edinburgh, Scotland); Citizen (UK); Height ( 6' 3"); Weight (210 lbs); Race (Caucasian); Hair (Brown - graying); Eyes (Brown). This is almost identical to Connery with the only differences being D.O.B (August 25, 1930) and Height (6'2). Mac's file also states; family (Age 5 - father died, age 12 - mother died, no known siblings); Marital Status (Widowed 1955, Camilla Charles); Languages Spoken (English, Mandarin, Japanese, French, Malay); and Military Service (Royal Marines 1956-1962, Commando Unit, Malaysian police). This is very similar to the character of James Bond. Family (Age 11 - both parents died, no siblings); Marital Status (Widowed in the book 'On Her Majesty's Secret Service'); Degree in Oriental Languages, fluent in French; Military Service (Commander in the Royal Navy).
An early scene, in which Gin sneaks into Mac's hotel room, and leaves the Time magazine on his bed, was deleted, but can be found (without audio) on the DVD. Jon Amiel said test audiences thought the scene unnecessarily delayed the first encounter between Gin and Mac.
During Catherine Zeta-Jones' breakdown of the intensive security measures she and Sean Connery will encounter in the millenium heist, Rolf Saxon is continuously shown throughout the sequence as the director of the millenium compliance testing. He was introduced in a similar fashion, as C.I.A. Analyst William Donloe when Tom Cruise conducts the breakdown of the C.I.A. break-in at Langley, Virginia in Mission: Impossible (1996).
In Ving Rhames following film, Mission: Impossible II (2000), the main protagonist, American spy Ethan Hunt (Tom Cruise), recruits professional thief Nyah Nordoff-Hall (Thandie Newton) to recover a stolen item, later revealed to be an engineered virus. Sean Connery, who plays Mac, is famous for playing British secret agent James Bond, and Rolf Saxon (Director) had played CIA Analyst William Donloe. Ving Rhames played IMF operative and computer specialist Luther Stickell in the "Mission: Impossible" franchise.
Pudu Station, where the protagonists meet at the end, is in fact Bukit Jalil Station, with all the signs changed. Bukit Jalil is a much more attractive station than Pudu, but too far from central Kuala Lumpur, to be feasible for the plot.
The film had a different original ending with Gin, not being the thief that the FBI were looking for. The undercover assignment was a set up by Hector, with help from Mac, Aaron Thibadeaux, and Conrad Greene; these three staged the whole thing, to frame Gin for the theft of the mask, and the eight billion dollars. Hector is revealed as the thief, and that he made a deal with Mac, to help him frame Gin, in exchange for his freedom after the FBI arrested him.