A nice, large version of her famous youthful nudity in Dangerous Liaisons
UPDATE:
I guess you can debate whether her screen nudity debut was in this film or Baron Munchausen. It depends on whether you define it by when she did it or when it was seen. This film was released earlier in both the UK and the USA, but Munchausen was filmed earlier. I suppose the filming date would mean that Munchausen was the first time she undressed for a film, so we can call that her debut by that definition, even if the film was not released quickly enough for it to be seen first. I have to agree that it is more sensible to define it by when she first undressed for a film.
OF NOTE: Munchausen was lensed between September 21, 1987 and March, 1988, so Uma was 17 at the time. She would not turn 18 until a month after filming ended. Uma’s having posed nude for a mainstream film at age 17 was not considered as scandalous at the time as it would be today. It was fairly common for mainstream films to feature nude scenes from actresses less than 18. Some examples: you all know about Brooke Shields, who was 12 when she bared all to play a child prostitute in Pretty Baby; Phoebe Cates was 17 she bared all in Paradise; Nastassja Kinski was 14 when she did her full-frontal scene in To The Devil a Daughter. The Brooke Shields nude scenes were shocking then, and even more so now, because she clearly looked like a child, but I don’t remember any intense discussions about Cates or Kinski when those films were released.