In 1984, Roos took part in the German national final for the Eurovision Song Contest for the fifth and last time so far and she sang herself to victory again: "Aufrecht geh'n" narrowly won the ticket to the Eurovision Song Contest 1984. At the contest, the song only received 34 points and finished 13th among the 19 contestants. Mary Roos was blamed for a bad vocal performance which she says was caused by an emotional crisis after her separation from her husband Werner Böhm. "Aufrecht geh'n" would also be her last appearance in the single charts until 1999, when she released a German cover version of Cher's song "Believe" ("Leider lieb ich dich immer noch"). Today, she still has many live concerts and is said to be one of the most-booked singers of the schlager genre. In 1985 Roos covered some C. C. Catch and Modern Talking's songs in German, including "You're My Heart, You're My Soul" (as "Ich bin stark, nur mit Dir"], and "I Can Lose My Heart Tonight".