A lot of the humor is slapstick and action-oriented, but there is some pretty funny dialogue too.
From Terry-Thomas, as J. Algernon Hawthorne:
"As far as I can see, American men have been totally emasculated — they're like slaves! They die like flies from coronary thrombosis while their women sit under hairdryers eating chocolates and arranging for every second Tuesday to be some sort of Mother's Day! And this infantile preoccupation with bosoms. In all my time in this godforsaken country, the one thing that has appalled me most of all is this preposterous preoccupation with bosoms. Don't you realize they have become the dominant theme in American culture: in literature, advertising and all fields of entertainment. I'll wager you anything you like that if American women stopped wearing brassieres, your whole national economy would collapse overnight."
From Ethel Merman, as Mrs. Marcus, describing her son, Sylvester, played by Dick Shawn:
"Exactly like your father: a big, stupid, muscle-headed moron!"
In the '80s I worked briefly for Troma Films and one of my coworkers brought in an a reel from the film and we watched it on lunch break. It was a blast seeing it in such large-scale, and in fairly close quarters. It's A Mad, Mad, Mad, Mad World is one of director Stanley Kramer's, who was known more for dramatic movies (Guess Who's Coming to Dinner, Ship of Fools, Judgment at Nuremberg, On the Beach) best-known films. It never fails to make me laugh out loud, which is the entire point of the film, and a real treasure, indeed.