Agnew is currently Distinguished Professor of Geography at the University of California, Los Angeles (UCLA). From 1975 until 1995 he was a professor at Syracuse University in New York. Dr. Agnew teaches courses on political geography, the history of geography, European cities, and the Mediterranean World. From 1998 to 2002 he chaired the Department of Geography at UCLA.

He has written widely on questions of territory, place, and political power. He has also worked on issues of "science" in geography and how knowledge is created and circulates in and across places. He is best known for his work completely reinventing "geopolitics" as a field of study and for his theoretical and empirical efforts at showing how national politics is best understood in terms of the geographical dynamics of "places" and how they are made out of both local and long-distance determinants. Much of his empirical research involves Italy, Greece, and the United States.