The domino scene, where V tips over black and red dominoes to form a giant letter V, involved 22,000 dominoes. It took four professional domino assemblers 200 hours to set it up.
For the scene when V emerges from Larkhill, stunt double Chad Stahelski literally walked through fire, wearing just a special fire resistant gel and a g-string. Stahelski's body temperature had to be lowered before the scene was shot, and luckily, it was three degrees below zero the night of the shoot. Fifteen minutes before a take, he would put on ice cold flame resistant clothing, and once he took them off, he would be covered with fire resistant gel which had been icing all day long.
The cast and crew were only allowed to shoot near the British Parliament and Big Ben (the clock tower) from midnight to 4:30 a.m., and they could only stop traffic for four minutes at a time.
One of the major challenges in this movie was how to bring V to life from under an expressionless mask. Thus, considerable effort was made to bring together lighting, acting, and Hugo Weaving's voice to create the proper mood for the situation. Since the mask muffled Weaving's voice, his entire dialogue was re-recorded in post-production.
Evey mentions to Gordon Dietrich that "eggie in the basket" is the same breakfast V made for her the first morning she spent at his place. She fails to mention (or doesn't notice) that Dietrich and V also greeted her in exactly the same way, not with "good morning", but with "bonjour mademoiselle". Also, Stan Getz is playing in the background in both instances.