The Things They Carried tends to get challenged or even removed from school libraries due to its mature content. Taking place during the Vietnam War, the book chronicles the experiences of young American soldiers traumatized by their time in the military, and these experiences often feature profanity and violence. For example, O'Brien describes a man's mangled corpse in great detail. Sexual themes are also prominent in the book, often arising in the longing the soldiers feel for their girlfriends back home. Some have even argued that the book is "anti-American" due to its criticisms of American foreign policy and the American military.

High school libraries and reading lists that include the book tend to be challenged frequently. One parent protested that they would not permit their teenage child to go to movies with the content that is in The Things They Carried; thus, they argued that schools should not teach such content in written form.

For most defending the retention of the book in school libraries, the graphic violence and profanity in The Things They Carried are not frivolous but realistic. The intent is not to be "vulgar," as one challenger has labeled the book; rather it is to reflect the daily misery and tension American soldiers felt during the Vietnam War, making the book a valuable resource for those learning about that conflict or about the experiences of soldiers more generally.