Getting Dev Anand for Jewel Thief wasn't a problem. But getting Ashok Kumar, the only one who Goldie was convinced could carry off the role of the suave villain, was difficult. Dadamoni had just returned from a heart surgery and when Goldie trekked to Roop Tara studio with the intention of getting his okay, he knew he had a task on his hands. Dev Anand introduced him to Dadamoni saying, "Goldie wants to make a film with you." After that the younger Anand took over, telling Dadamoni that he was making a two hero project. "I want you to play the title role. It's a very challenging role. The only problem is that we learn in the last reel that your character is the film's bad man. But you've played the anti-hero before. You can do it. In fact, only you can do it. You're a courageous actor, yes, you are," Goldie coaxed the veteran actor. Ashok Kumar was game. But he laid down three conditions. "I'm not going to hit anyone. And no one should hit me. If I get into fisticuffs it'll kill me," he warned Goldie. Goldie assured him that there would be no fights. His villain was an intellectual villain. He uses his mind, not his muscles. Dadamoni was relieved to hear that. His final condition was that he would report on the sets at 11 a.m. sharp with make-up on. Two hours later they'd break for an hour-long lunch break. And at 5 p.m. it would be "pack-up". That too was agreeable to Goldie. He assured Dadamoni that his schedule would be followed to the minute. On the first day Dev Anand and Ashok Kumar were on the sets at 11 a.m. sharp. But there was no sign of the film's heroine, Vyjayantimala. An assistant was sent to her every quarter of an hour. Finally, at 12.30 he returned with the message that madam didn't want to be disturbed, she'd come when she was ready. At ten minutes to one she strolled in asking sweetly, "Am I late?" Goldie surprised her by calling for a lunch break. Vyjayantimala was furious. "Your assistant has been badgering me for the last two hours and now when I'm here you announce a break," she raged. Goldie was unfazed. "Our most senior artiste is not a very healthy person. We have to follow his schedule. You have to be on the set early," he reminded her. Vyjayantimala never forgot the "slight". For the rest of the film, Goldie insists, she nursed a khunnas against him. There were some date problems and many distractions but Vyjayantimala being the professional that she was, still came up with a polished performance. Goldie's only grievance is that she could have done better with Hoton pe aisi baat. "I wanted her to rehearse the number before we went for a final take. But she told me airily that she didn't need any rehearsals. I insisted she did, but she still didn't report for rehearsals and came straight to the set. I called for "pack-up" and told her firmly that she had to stay back in the studio and practise with the assistants. She did practise, for 15 minutes. Then she got into her car and drove off saying that Saroj Khan would be coming to her place later and they'd go over the steps together. The rehearsal never happened but Vyjayantimala being a good actress and an excellent dancer didn't find it too difficult to pick up the steps and the shots were okayed quickly. But I could never establish the kind of rapport I had with Mumtaz, Waheeda, Hema and Raakhee, with Vyjayantimala," Goldie rues
Director Vijay Anand first offered the role played by Ashok Kumar to Raaj Kumar. Raaj Kumar decided against it due to Dev Anand being the producer and lead actor of the film.
Yeh Dil Na Hota Bechara was sampled from the theme of "The Bridge on River Kwai" ( Colonel Bogey March by Kenneth J. Alford). The TV show character "Carlton Banks" from the TV show Fresh Prince of Bel Air sang his own version called "Peacocks" in a episode. Colonel Bogey March March by Kenneth J. Alford was also in the final scene of Prem Aggan.
The voice on the phone when "Amar" calls Helen while she is with Vinay (who is pretending to be Amar) is actually that of director Vijay Anand.
28 years later the sequal of this film came. Ashok Kumar and Dev Anand were the only actors who were in Jewel Thief.
Helen's brother Roger Jairag ( Richardson) appeared in the song Baithe Hain Kya Us Ke Paas as a navy man by the bar.
In "Jewel thief", the background music played during Dev Anand - Helen scene at Helen's apartment, was recycled by RDB in "Carvan" for the song "Piya tu ab to aaja"..
The Twilight Zone's theme music was slightly sampled in the title music and background music used in the film. Vijay Anand can be heard giggling in the title music.
For the lead female role, Saira Banu was approached by Dev Anand. Banu, who had earlier worked with Anand in "Pyar Mohabbat" (1966) declined the role due to her marriage to actor Dilip Kumar.
R.D. Burman acted as an assistant to his father S.D. Burman who was the music director for this film.
Tanuja in this movie looked very beatiful than in any other films.30 years ofter this film Tanuja acted in Navketan's Main Solah Baras Ki. Tanuja after long time looked beautiful.