Arnold Schwarzenegger worked with guns every day for a month to prepare for the role. The first two weeks of filming he practiced weapons stripping and reassembly blindfolded until the motions were automatic, like a machine.
He spent hours at the shooting range and practicing with different weapons without blinking or looking at them when reloading or cocking. He also had to be ambidextrous. He practiced different moves up to 50 times.
He wound up garnering a compliment in "Soldier of Fortune" magazine for his realistic handling of the guns on camera (whereas the magazine usually lampoons movies for their inaccurate depictions of weapons use).
One afternoon during a break in filming, Arnold Schwarzenegger went into a restaurant in downtown L.A. to get some lunch and realized all too late that he was still in Terminator makeup - with a missing eye, exposed jawbone and burned flesh.
O.J. Simpson was considered for the Terminator, but the producers feared he was "too nice" to be taken seriously as a cold-blooded killer. In 1990 (before Simpson's first trial) Dark Horse Comics printed issues using his likeness.
Arnold Schwarzenegger tried to avoid Linda Hamilton and Michael Biehn as much as possible since the Terminator was trying to kill them, not forming connections.
原本卡導FOR T1的劇本就是雙終結者（另一位為T1000），然後男主應該要阻止這兩位XD 但是他考量了當時的CLAY（黏土？）技巧沒有辦法做到他想要的效果，而且對於這麼龐大的故事以他當時的名聲想賣給STUDIO也不願意買帳，所以他T1就只用了前半的故事。
這個原始劇本當初卡導以1塊錢美金賣給了他的製作搭檔Gale Anne Hurd，唯一條件是她必須盡一切努力讓這片能開拍，而且導演一定要是他。
Arnold Schwarzenegger was originally being considered to play Kyle Reese instead of the Terminator.
Cameron and Schwarzenegger have been good friends ever since.
Michael Biehn almost didn't get the role of Kyle Reese because in his first audition he spoke in a Southern accent as a result of working on a part for a stage production of "Cat on a Hot Tin Roof" (he didn't get the role)
Sarah Connor is 18 years old in the movie. This is proven in the sequel Terminator 2: Judgment Day (1991) where Dr. Silberman says Sarah is 29 years old and T-1000 checks Sarah son's, John Connor's, profile which states he's 10 years old, having been born when Sarah was 19.
Mel Gibson turned down the role of the Terminator, simply feeling he wasn't right for the part. After seeing the film, he praised Arnold Schwarzenegger as a much better choice.
Wolfie, James Cameron's German Shepherd dog, can be seen at the Tiki Motel
Kyle Reese was originally 21 years old. Michael Biehn was 27.
Several years of working on Roger Corman movies had tought him all the tricks of the low-budget trade, so Cameron was able to solve a lot of logistical and practical issues on the set himself.
Though she's a registered Democrat, Linda Hamilton voted for Arnold Schwarzenegger, the Republican candidate, in California's 2003 recall election that saw Schwarzenegger become the state's governor.
Due to changes in copyright law, they reverted back to him in 2019 after 35 years, but he received no royalties for any of the movies made during that time. He refers to this lost income as "the costs of a Hollywood education".
Mickey Rourke was considered for the role of Kyle Reese.