This show existed in the same universe as Hulk and the Agents of S.M.A.S.H (2013) and Marvel's Guardians of the Galaxy (2015), The first 4 seasons crosses over with Ultimate Spider-Man (2012). The last season, however, crosses over with Marvel's Spider-Man (2017) instead.
Adrian Pasdar, who voices Iron Man/Tony Stark on the show, also plays General Glenn Talbot on Agents of SHIELD.
Fred Tatascoire is the only voice actor to voice a character, in his case Hulk, in both The Avengers Earth's Mightiest Heroes and Marvel's Avengers Assemble. Bumper Robinson was also in both series; as James 'Rhodey' Rhodes/ War Machine in Earth's Mightiest Heroes, and as Falcon on Avengers Assemble...
The original concept of Captain America from the 1940's comic was created by the artists using the Actor Fred MacMurray's face and body as the basis for Steve Rogers physical look in the comics.
In an alternate Marvel Universe, the world's superheroes become zombies. When Zombie Spider-man forms the New Avengers, their call is AVENGERS DISMEMBER!, a reference to the iconic Avengers assemble phrase.