Patrick's inheritance is managed by Dwight Babcock, a trustee of the highly conservative Knickerbocker Bank, who was appointed in Edwin's will to restrain Mame's liberal influence.

During one job as a Macy's salesgirl, Mame meets Southern oil baron Beauregard Jackson Pickett Burnside, who seeks her out to relieve her distress when she is fired due to her ineptitude on his large toy order to orphans.

After Beau dies while climbing the Matterhorn in 1937, Mame, now a rich widow, comes home after a prolonged period of mourning to discover the now-adult Patrick has given her a dictaphone, typewriter, and secretary, Agnes Gooch.

When an inebriated Agnes returns, she barely remembers the evening; she thinks they saw a movie with a wedding scene and that O'Bannion was keen to meet her mother but abandoned her on the way to the working-class neighborhood.

The entire party is choreographed to show up the Upsons: Lindsay surprises the attendees with galleys from Mame's autobiography, reminding Patrick of forgotten adventures.

The Motion Picture Herald review observed that the film "provided a unique means of establishing time and plot progression" through the changing decor of Mame's Beekman Place apartment.

[6] The New York Times critic Bosley Crowther observed: "The lavish décor of Mame's apartment is changed almost as frequently as are her flashy costumes, and all of them are dazzling, in color and on the modified wide-screen.

In an article describing why Turner Classic Movies has named it one of “The Essentials”,[8] Andrea Passafiume observes that the role transformed Russell's career, “first on the Broadway stage and then on the big screen.

The role of Mame Dennis... gave her the chance to be glamorous and showcase her sharp comedic talents, which reminded the world that she was still a vital force to be reckoned with.

[9] The movie premiered at the Radio City Music Hall, and Bosley Crowther of The New York Times wrote that "for all its absurd exaggerations and bland inconsistencies, this picture of a tireless party-giver is a highly entertaining thing to see.

"[10] Harrison's Reports called the film "a fast and furious comedy, with a glamorous background and considerable deep human appeal ... Rosalind Russell, who scored a huge success in the stage play, repeats her wonderful performance as the uninhibited heroine in this screen version.

Rosalind Russell, who created the part on the stage, takes a turn or two to get into her stride; once established, however, her superbly confident timing and powerfully empathic comedy personality see her happily through.

For about the first third, it is diverting high comedy growing out of credible characters; then, for fear of losing momentum, the writers start to pump in gags and gaggy situations.