!!The 1959 series:

* HeyItsThatGuy:
** Ness is the pilot from ''Film/{{Airplane}}'' and the guy who hosts ''Series/UnsolvedMysteries''. He is epic in all of them.
** Robbins became both a [[Series/{{JAG}} naval aviator and lawyer]].

!!The 1987 movie

* DyeingForYourArt: [=DeNiro=] gained 30 pounds for his role as Capone, and (allegedly) even insisted on wearing the same clothes Capone did, right down to his silk underwear.
* FakeNationality: Sean Connery as an Irishman, Cuban-American Andy Garcia as an Italian-American (first generation).
* HeyItsThatGuy: Recognize the alderman who presents Capone's bribe to Ness early in the film? That would be Chicago teacher/actor/improv superhero Del Close.
* StarMakingRole: For Creator/KevinCostner and Creator/AndyGarcia.
* ThrowItIn: Costner ad-libbed the line "He's in the car," after [[spoiler:throwing Nitti off of the roof]].
* WhatCouldHaveBeen:
** Creator/HarrisonFord turned down the role of Eliot Ness.
** Creator/BobHoskins was cast as Al Capone, but was paid a bundle of money once [=DePalma=] brought [=DeNiro=], the director's first choice all along, onboard.