Spider-Man referred as "Peter Palmer" in the second story of The Amazing Spider-Man (I) #1.
Doctor Octopus calls Spider-Man "Super-Man" in The Amazing Spider-Man (I) #3.
Betty Ross called "Miss Brant" by Glenn Talbot and Rick Jones in Tales to Astonish (I) #61 and #62; She corrects neither.
Hawkeye refers to his "powerful gloved hands" even if he never wears gloves (his hands are visibly gloveless on the same picture) in the Iron Man story in Tales of Suspense (I) #57.
Beast says "violence is the last refuge of the incompetent" (obviously, that should have been "first refuge") in X-Men (I) #10.
The Angel was called "Scott" all through X-Men (I) #36.
Marvel Girl levitates a screwdriver to Beast and refers to it as "pliers" in X-Men (I) #28; Beast responds with "You're a credit to your gender, Jeannie".
Reed has two left hands on the title page of Fantastic Four (I) #88.
One of Reed's feet is replaced with a hand on title page of Fantastic Four (I) #152.
Wasp has wings on normal human size in Tales to Astonish (I) #50.
Rick Jones tells to the Space Phantom (masquerading as Hulk) that he's able to turn back to Dr Don Blake in Avengers (I) #2.
The Grim Reaper shown having two hands in Avengers (I) #160.
Captain America jumps out of a plane and opens a parachute in Tales of Suspense (I) #74, but first page of #75 shows him falling without that.
The Thing is flying a jet while holding a broken wing in Marvel Two-In-One #41.
Hercules dragging Manhattan Island in Marvel Team-Up (I) #28.
Black Bolt destroys the Great Barrier in Fantastic Four (I) #59, but Reed Richard takes the credit for it in Fantastic Four (I) #82.
Captain Barracuda looks into a periscope with the eye which has an eyepatch on it (in The Incredible Hulk (II) #219).
Ego tells Galactus he's not as "invisible" as he seems eight years later in Thor (I) #161.
Professor X telepathically warns a bed-ridden Beast not to tell the doctors his secret identity -- then calls him on his last name out loud (X-Men (I) #17).
Daredevil wearing a holster and pulling out a gun (Daredevil (I) #29).
Beast wearing gloves on title page of X-Men (I) #2.
Captain America's uniform has an "A" instead of the white star on his chest on cover of Avengers (I) #21.
Scarlet Witch featured on the cover of Avengers (I) #33 but not in the issue.
The location of the Great Refuge is inconsistent (the Andes in Fantastic Four (I) #47, the Himalayas in Fantastic Four (I) #82, the Alps in Incredible Hulk Annual #1 and the Moon in Fantastic Four (I) #240).
Cap's shield destroyed (which is already impossible), and shown eight panels later without any kind of explication (Avengers (I) #35).
Ant-Man and Wasp trapping Loki in a lead-lined tank (even if no kind of prison can hold Loki) (Avengers (I) #1).
Iron Man referring to his "transistor-powered" jets. Transistors don't power anything. (Tales of Suspense (I) #39)
Thor, who supposedly cannot be felled by anything physical, succumbs to chemicals (which are physical) (Avengers (I) #13).
Both cover and title page of Tales of Suspense (I) #44 misspells "pharaoh" as "Pharoah".
Captions say "Muriela turned waitress" but that's supposed to be "traitress" (The Savage Sword of Conan #25).
Marvel Two-In-One #1 has a "Marvel Two-on-One" on the upper left corner.
Inconcordances about the girl from Steve Rogers' past (Tales of Suspense (I) #75, #76, #77, Captain America (I) #162).
The Thing blows down a door with his "super-breath" in Fantastic Four (I) #87.
In Fantastic Four (I) #88 a point was made that the Thing isn't with them, but next issue he inexplicabily appears.
Daredevil's coin toss in Giant-Size Defenders #3 (Grandmaster calls "tails", it is tails, but DD says that it's heads and the Grandmaster buys it).
Cap's shield strapped to his back, which should be much larger than his actual waist (Captain America (I) #206).
Ant-Man is supposed to be ant-sized, yet he can ride them -- also, when he's standing, he seems a couple inches tall. Wasp is supposed to be wasp-sized, yet she is about the same size as he is. (Tales to Astonish (I) #44)
The Savage Land referred as being on the Arctic instead of the Antarctic (Ka-Zar (II) #15).
Zabu gets a tail in Daredevil (I) #12.
Someone has two left feet in Daredevil (I) #172.
A Subterranean "thinks" Iron Man's caption in Avengers (I) #12.
Iceman whips up some ice-cream on the first page of X-Men (I) #6 (without milk, sugar and rock salt).
Giant-Man's fan club surprises him without his mask on before his secret identity revealed, and no one's surprised (Tales to Astonish (I) #54).
An unmasked Dr. Pym while Iron Man looks on, long before Iron Man knew his secret identity (Avengers (I) #58).
Jason Wyngarde's name (X-Men (I) #125 claims "the name is as false as the man himself", #138 claims "his real name, ironaically enough").
Tales of Suspense (I) #92, Cap says "Only on of us is gonna walk out here -- under his own steam --", then "--And it won't be me!"