José Ferrer was transformed into the short artist Toulouse-Lautrec by the use of camera angles, make-up, costume, concealed pits and platforms, and short body doubles. Ferrer also used a set of special knee pads of his own design which allowed him to walk on his knees with his lower legs strapped to his upper body. He suffered extreme pain and could only use them for short periods of time. The cane he used in most of his scenes was of absolute necessity. This fact was covered in a LIFE Magazine story in 1952.
John Huston related in his autobiography that during the making of some sequences in the middle of the traffic in Paris, the Parisian motorists were so angry because of the shooting that they blew their horns very loudly, so loudly that the actors could not hear themselves. So they had to read each other's lips and were dubbed in post production.
When director John Huston appeared on the BBC's "Desert Island Discs" program in 1973, host Roy Plomley told him that this movie was a personal favorite of his. Huston replied "I don't think it's one of my best films," adding that 1950's censorship constraints had made it impossible to tell the story of Henri de Toulouse Lautrec's life honestly. As an example of some of the pettiness of censorship of the time, the amount of allowed bare skin on can can dancer's legs was debated.
In the film, Henri mentions three artists he claims died before they turned 40. Of those three, Raphael died when he was 37, Watteau when he was 36, but Correggio was 44 when he died. Like Watteau, Toulouse-Lautrec was only 36 years old when he died.
John Huston found out that Pablo Picasso himself was so interested in the shooting of the movie about the Moulin Rouge cabaret and Henri de Toulouse Lautrec that he rented a hotel room with a window just above the places where some scenes were shot.