R. Timothy Mulcahy earned his bachelor's degree in biology from the University of Rochester in 1973 and his doctorate in pathology and radiological sciences from the University of Wisconsin-Madison in 1979. In 1981, he joined the faculty of the Experimental Therapeutics program at the University of Rochester Cancer Center. In 1985, he was recruited to the University of Wisconsin, where he achieved the rank of full professor, in 1991.

Mulcahy's research has focused on cancer biology with an emphasis on the development of novel therapeutic approaches and on the molecular mechanisms of tumor cell resistance to conventional chemotherapy. His research has spanned the spectrum from bench research to clinical trials. His laboratory group is recognized for its expertise in the regulation of two key genes involved in critical cellular protection pathways. He has trained numerous graduate students, postdocs, and medical fellows and has published over 85 research papers in peer-reviewed journals.

In 1996, Mulcahy was appointed associate dean for the biological sciences in the University of Wisconsin-Madison Graduate School. In this capacity he had administrative responsibility for research and graduate education activities of 40 departments or programs, 676 faculty, and 1,690 graduate students in the biological sciences at the University of Wisconsin. In 2002, he was also appointed associate vice chancellor for research policy with responsibility for coordinating development and implementation of campus research policies.

In February of 2005, Mulcahy began his tenure as the University of Minnesota's Vice President for Research.