In 1951 Stich-Randall made her European debut in Florence, Italy, and that same year took first prize in an international singing competition held in Lausanne. This established Stich-Randall's reputation in Europe, and although she would perform with the Chicago Lyric Opera, at the Metropolitan in New York, and on American concert tours as a soloist in the coming years, it was in Europe that most of her subsequent activity was centered. Stich-Randall was named an Austrian Kammersängerin in 1962 and was the first American accorded this particular honor; afterwards, she was contracted to the Vienna State Opera and sang there primarily until her retirement around 1980. Outside of much-heralded visits home to West Hartford in 1982 and 1983, Stich-Randall had been little heard from after that.
Although Teresa Stich-Randall is hardly a household name, she had many fans among those who collect vintage vocal recordings. In her concert career she frequently sang works by Handel and J.S. Bach. Stich-Randall's approach to Baroque music was signified by her light tone with no more than a subtle vibrato, clear enunciation, and an infallible sense of pitch. Stich-Randall was definitely ahead of the game in regard to latter-day period performance practice, and her best recordings generously bear this out, in particular her 1966 Vanguard recording of Pergolesi's Stabat Mater with alto Elisabeth Höngen.