Brühl's first screen appearance was in the 1954 film Der letzte Sommer with Liselotte Pulver, but in the role of Dalli, in what became known as the "Immenhof films", she became famous in Germany. Die Mädels vom Immenhof, adapted from a novel by children's Writer Ursula Bruns, appeared in 1955 and was followed by two sequels, Hochzeit auf Immenhof and Ferien auf Immenhof, at yearly intervals. She returned to the role in Frühling auf Immenhof in 1974.
In 1959, Brühl obtained a record deal with the Philips label, and her first single "Chico Chico Charlie" reached number five. In 1960, her recording of "Wir wollen niemals auseinandergeh'n" or "We Will Never Part (Ring of Gold)" sold over one million copies, and was awarded a gold disc.
Brühl first took part in the German Eurovision selection in 1960 with the Michael Jary-composed "Wir wollen niemals auseinandergehen" ("We Never Want to Be Apart"), which finished in second place but went on to top the German singles chart for nine weeks. She participated again in 1963, and this time was successful when "Marcel" was chosen to go forward to the eighth Eurovision Song Contest which took place on 23 March in London. "Marcel" finished the evening in ninth place of 16 entries.
Brühl co-starred with Guy Williams in the 1963 film Captain Sindbad. She met American actor Brett Halsey, and moved with him to Rome, where they married in December 1964. In 1970, she moved to the United States where she appeared in Las Vegas and in episodes of such television series as Columbo "The Most Dangerous Match" (1973). She returned to Germany to play in two further Immenhof sequels in 1973-74, Zwillinge vom Immenhof and Frühling auf Immenhof. She appeared in The Eiger Sanction in 1975 as Anna Montaigne, the seductive wife of a French climber.
Brühl died of breast cancer on 8 June 1991 in Starnberg, aged 49.
