Continuity mistake: When Valmont visits Madame de Tourvel and enters her room, there's a servant standing next to Valmont who appears to leave and you hear the door close. In the next scene he is still standing there with the door closed and then takes Valmont's hat, opens the door, and leaves.
Continuity mistake: At the end of the duel the Vicomte de Valmont falls where he is hit, next to the wall; Danceny and Azolan rush immediately to his side. During his subsequent repentance and death, he is not moved. In the final, overhead, shot of the scene there is a long trail of blood in the snow and Valmont is not near the wall. (01:49:30 - 01:52:30)
Continuity mistake: When Valmont and Merteuil are at the party at the aunt's house, one of them takes a few steps away from the other while they're talking. In the next shot they're standing very close together.
Visible crew/equipment: Towards the end, as Vicomte de Valmont is demanding a simple yes or no, there's a shot of Marquise de Merteuil in front of a mirror, slowly panning back. Just after he says "yes or no," we see a shadow/silhouette in the mirror moving, but Valmont is standing perfectly still, and no one else is in the room.