Goofs

Near the end of the movie, D'Artagnan removes and drops his hat as he leaps into the water from the castle parapet. Seconds later, he is riding at full gallop with his hat on.

When D'Artagnan is in his room and Constance enters into the room below, he spies upon her by lifting the floorboard in his room to look down at her below. Later, when he goes down to her room to help her from her attackers, we see the ceiling above is made of plaster, not wood.

During the first sword fight scene, Gascon splashes water out of a bird bath into his opponent's face to distract him. After the fight is over, the musketeers walk away laughing and the camera rises to an overhead shot - the bird bath is now completely dry.

After the first sword fight after Jussac runs off with his trousers dripping, he leaves his sword behind. It can be seen as D'Artagnan walks back towards the musketeers. As the musketeers and D'Artagnan walk off laughing Jussac's sword has mysteriously gone.

In the battle on the beach (at around 1 min), D'Artagnan's opponent's horse is solid black in close-up, but brown with a white blaze in wide shots.

The storyline for the movie takes place in 1625, yet shows King Louis XIII as an old man. In reality, Louis (1601 to 1643) would have only been 24 years old at the time.

Over the first hour of the movie, Countess de Winter's mole is below and to the left of her mouth. When Richelieu introduces her to D'Artagnan, her mole is below and to the right of her right eye. When she breaks a mirror several minutes later, she has no mole at all. She then gets dressed and meets D'Artagnan in her parlor without a mole. During their conversation, it reappears near her right eye. When they start wrestling, the mole is again missing. The mole appears, disappears and moves throughout the movie. However, during this time, among the French upper class, women sometimes added a phony mole (or beauty mark) when applying their facial cosmetics.

During the first sword fight, Athos warns Porthos of a guardsman approaching from behind, Porthos turns around and engages him and ends it with a sword thrust. But the sword is clearly thrust between the guardsman's body and left arm, touching only a part of his clothing, although they close quickly to hide the fact.

At about 1:28 while Gene and June are sitting in the open window a piece of reddish fabric falls down from the upper right and casts a shadow on the two as it falls.

During the fight scene on the stairs, D'Artagnan pushes the guard with the spear over the railing on the stairway. As the guard falls, the hands of a crew member are seen reaching out to grab his legs.