He also wrote and illustrated several books featuring Dennis, including:
* Dennis the Menace (1951)
* Dennis the Menace on the Job (1952)
* Dennis the Menace and How to Get Away with It (1953)
* Dennis the Menace and the Girl Next Door (1954)
* Dennis the Menace Goes to School (1955)
* Dennis the Menace and the World Around Him (1956)
Ketcham also wrote and illustrated other comics, including:
* The Family Circus (1960-1989)
* The Right Way to Do It (1961-1962)
* The Happy Times (1962-1963)
He was also a prolific cartoonist, illustrating for various magazines and newspapers.