In 1992, Tunick began documenting live nudes in public locations in New York through video and photographs. His early works from this period focus more on a single nude individual or small groups of nudes. Tunick cites 1994, when he posed and photographed 28 nude people in front of the United Nations building in midtown Manhattan, as a turning point in his career: "It all started there, moving my work from just photography into installation and performance photography," he says. Since then, he has organized and photographed over 65 temporary site-related installations in the United States and abroad.
Tunick's philosophy is that "individuals en masse, without their clothing, grouped together, metamorphose into a new shape. The bodies extend into and upon the landscape like a substance. These grouped masses which do not underscore sexuality become abstractions that challenge or reconfigure one's views of nudity and privacy." After gathering his subjects together, Tunick grades them by gender, long hair, age or other characteristics. Registration for modeling on his website includes questions about skin tone. A colour chart shows seven boxes ranging from stark white to baby-powder pink and dark chocolate. In his work, he plays off different flesh tones or groups people of the same colour. Tunick is also interested in the juxtaposition between the organic and the mechanical, and often chooses famous buildings or unusual structures as his backdrop.