There he met and married American exchange student Mary Vangeli, and they moved to the United States in 1957. He soon became a naturalized US citizen, and after working in the US Foreign Service Institute as an Italian instructor, he began graduate studies at the Catholic University of America, earning a PhD in Romance Languages and Literatures in 1966. After teaching at the University of Virginia, Charlottesville and the University of Wisconsin, Milwaukee, Lèbano arrived at IU in the fall of 1971 as an Associate Professor with tenure.

Soon after his arrival at IU and with the support of his Italian colleagues, Lèbano advocated for the creation of a Center for Italian Studies, which was approved in 1974, with Lèbano as its first director. He was also very active in study abroad programs, creating the IU Bologna summer program for which he served as director for two years, and directing both the Bologna academic year program and the Florence summer program twice.

Lèbano's research achievements, teaching excellence, and prodigious service were recognized through promotion to the rank of Professor in 1983. His scholarship focused on three different fields: Renaissance epic and chivalric poetry, with an emphasis on the works of Luigi Pulci; nineteenth century and Modernism; and language instruction. Perhaps his most influential scholarly work is the first English edition, translated in verse by the Italian American poet Joseph Tusiani, of Luigi Pulci's epic poem Morgante. He was also the co-author, with Pier Raimondo Baldini, of one of the major Italian textbooks in the United States for decades, Buongiorno a tutti!.

A beloved teacher, Lèbano garnered student praise such as "Brilliant, very animated with a colorful imagination" and "Sometimes too enthusiastic, if that is possible." He spread Italian outside the classroom too, cooking dinner for students in the campus Food Services Building in the 1970s, leading a 13-day "epicurean experience" through northern and central Italy in the summer of 1983, and contributing his famous lasagna to the Department's annual holiday party for years into his retirement.

An influential figure in the teaching of Italian language and culture in the US, Lèbano served the American Association of Teachers of Italian (AATI), first as secretary-treasurer (1980-1983) and later as president ( 1984-1987). He taught for many summers at the Middlebury College Italian School, arguably the best full-immersion program in North America, where he served as director from 1987 to 1995. It was under his direction that the Middlebury Italian School acquired the international reach and prestige it still has today.

Edoardo Lèbano's service and leadership have been recognized by significant accolades including the AATI Distinguished Service Award and the title of Cavaliere dell'Ordine al Merito della Repubblica Italiana bestowed by the President of the Italian Republic.