Renowned for his innovative teaching methods and the wide-ranging nature of his repertoire, Ericson was the principal conductor of the Orphei Drängar choir at Uppsala University from 1951 until 1991, and choirmaster until 1982 of the Swedish Radio Choir which was established on his initiative in 1951. Also in 1951, he began his teaching career at the Royal College of Music in Stockholm, where he became a legendary and inspirational figure, and he was appointed to the chair of choral conducting there in 1968.
He won the Nordic Council Music Prize in 1995, and in 1997 Ericson shared the Polar Music Prize with Bruce Springsteen: the citation was for "pioneering achievements as a conductor, teacher, artistic originator and inspirer in Swedish and international choral music". On the occasion of his 80th birthday in 1998, Swedbank of Sweden endowed an "Eric Ericson Chair in Choral Directing" at Uppsala University.
His conducting for the 1975 Bergman film The Magic Flute was described as "impressive" in its balance of "levity and solemnity", and the reviewer noted that Ericson was "a Mozartian to be reckoned with".