He taught politics and philosophy at Bennington College in Vermont and for more than 20 years was a professor of management at New York University's graduate business school.
Beginning in 1971, he taught a course for mid-career executives at Claremont Graduate School in California, which has named its business school after him.
Drucker's management books included: The Effective Executive (1966); Management: Tasks, Responsibilities, Practices (1974); and Managing in a Time of Great Change (1995). Last year, he put out The Daily Drucker: 366 Days of Insight and Motivation for Getting the Right Things Done.
He also wrote scores of articles for the academic and popular press, two novels and an autobiography, Adventures of a Bystander.
While much of his career was spent studying employees in the workplace, Drucker also dedicated time to the service sector, founding the New York-based Peter F. Drucker Foundation for Nonprofit Management, known since 2003 as the Leader to Leader Institute.
Jack Beatty, a senior editor at Atlantic Monthly magazine who wrote the book The World According to Peter Drucker, described the management guru as "uproariously funny [with] a great rapport. You ask him a question and it can go on for some time."
Drucker is survived by his wife, Doris, and four children.
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