Although he began working on modern Chinese literature under Professor Liu Wuji 柳無忌 (1907-2002), the year he spent studying Tang literature under Professor Peter Olbricht at Bonn directed him towards working on Liu Zongyuan 柳宗元 (773-819) and Tang fiction.
In 1973 Nienhauser edited a volume of essays on Liu published in the Twayne World Author Series and took up a position as assistant professor in the Department of East Asian Languages and Literature at the University of Wisconsin-Madison.
The following year he began to edit what has now become eight volumes translating and commenting on 92 chapters of Sima Qian's Shiji 史記 in cooperation with nearly 70 scholars from the U.S., Germany, China, Japan, Romania, and Italy.
Later that year he won the Special Book Award of China as the only American among fifteen international winners for his work on the Shiji.
His publications include the two-volume Indiana Companion to Traditional Chinese Literature and eight volumes of translations from the Shiji (The Grand Scribe’s Records).