Ditko schooled at the Cartoonists and Illustrators School in New York City under Jerry Robinson. Began professionally illustrating comic books in 1953. His early works were for Charlton Comics, producing science fiction, horror and mystery stories. Ditko then began working for what would become Marvel Comics.
He created (or co-created, according to some) the superhero characters of Spider-Man and Doctor Strange for Marvel. His idiosyncratic art style emphasizing mood and anxiety found favor with the reading public. The character of Spider-Man with his anxiety, angst and troubled social life meshed well with Ditko's personal style and interests. After a run of four years on the title, Ditko is believed to have had a falling out with writer/editor Stan Lee and left the company. The exact details of this are uncertain to this day.
He is said to have shared a studio with bondage artist Eric Stanton in the period 1958 to 1966.
He returned to Charlton where he produced such titles as Captain Atom, Blue Beetle, and The Question. In the pages of The Question Ditko began infusing his own philosophy which stemmed from Ayn Rand's objectivism.
By 1968, Ditko was producing work for DC Comics where he created characters such as The Creeper and The Hawk and the Dove. Ditko used these tales, ostensibly in the superhero genre, to espouse and explore various ethical issues. Either because many readers found the preachiness in some of these stories unpalatable, or perhaps due to disagreement with the artist's philosophy, Ditko's work was not as popularly received as previously. Ditko's more personal projects, such as Mr. A and Avenging World, display his political sentiments vividly, and have demonstrated little commercial appeal.
Ditko currently resides in New York City. Though a prolific and hard-working artist he is also an intensely private man. Preferring to let his work speak for itself, he has refused interviews, profiles and public appearances.