Diana Eck's academic work has a dual focus—India and America. Her work on India focuses on popular religion, especially temples and places of pilgrimage, called tirthas. Her books include Banaras: City of Light and Darsan: Seeing the Divine Image in India and her most recent work, India: A Sacred Geography, published in 2012.
Her work on the United States focuses especially on the challenges of religious pluralism in a multireligious society. Since 1991, she has headed the Pluralism Project, which explores and interprets the religious dimensions of America's new immigration; the growth of Hindu, Buddhist, Sikh, Jain, and Zoroastrian communities in the United States; and the new issues of religious pluralism and American civil society. The Pluralism Project's award-winning CD-ROM, On Common Ground: World Religions in America, was published in 1997; her book A New Religious America: How a "Christian Country" Has Become the World's Most Religiously Diverse Nation was published in 2001. Her book Encountering God: A Spiritual Journey From Bozeman to Banaras is in the area of Christian theology and interfaith dialogue. It won the Grawemeyer Book Award in 1995, and a 10th-anniversary edition was published in 2003.
Eck received the National Humanities Award from President Clinton and the National Endowment for the Humanities in 1998, the Montana Governor's Humanities Award in 2003, and the Melcher Lifetime Achievement Award from the Unitarian Universalist Association in 2003. In 2005-06 she served as president of the American Academy of Religion. Eck has worked closely with churches on issues of interreligious relations, including her own United Methodist Church and the World Council of Churches. She is currently chair of the Interfaith Relations Commission of the National Council of Churches. In 2009 Eck delivered the Gifford Lectures at the University of Edinburgh, a series of six lectures titled "The Age of Pluralism."