His daughter, Debbie Bookchin, told The New York Times that he suffered from a malfunctioning aortic valve.
Bookchin was born in 1921 in New York to a family of Russian immigrants. He joined a communist children's organization when he was 9 and was expelled from the party at the age of 18 for Trotskyite tendencies, the Times said.
After military service in World War II, Bookchin worked for General Motors, where he became a labor activist. His political views evolved into anarchist socialism, the newspaper said.
Although he never graduated from college, Bookchin eventually became a tenured professor at Ramapo College, a New Jersey state institution. He also founded the Institute for Social Ecology in Plainfield, Vt.
His books include "The Ecology of Freedom: The Emergency and Dissolution of Hierarchy" and "Our Synthetic Environment," which questioned the use of chemical pesticides and was published six months before Rachel Carson's "Silent Spring."