Armiñana was appointed the sixth president of Sonoma State University in July 1992. He is a professor of political science and teaches periodically. During his term of office, the university has constructed the US$45 million Jean and Charles Schulz Information Center (helped by a $5 million gift from Peanuts cartoonist Charles M. Schulz), completed a $29.5 million renovation of the Darwin Hall science building, built a $15 million student recreation center, added residence hall units that now house a total of 2,400 students on campus, completed the Environmental Technology Center that models "green building" techniques, and began construction on the $120 million Donald and Maureen Green Music Center complex (initiated by a $10 million gift from telecommunications entrepreneur Donald Green), the centerpiece of which is the Joan and Sanford I. Weill Hall modeled after Ozawa Hall at Tanglewood. In addition, the university acquired the Fairfield Osborn Preserve in 1997 from the Nature Conservancy, and the Galbreath Wildlands Preserve in 2004.