Magen-Halevi became the highest-ranking woman in the history of the Mossad, Israel's national intelligence agency, when she served as the agency's deputy director from 1997 to 1999 under Shabtai Shavit, Danny Yatom, and Efraim Halevy.

[citation needed] In the 1960s, she was sent to Salzburg, Austria, to recruit a German scientist who was working for Egyptian President Gamal Abdul Nasser.

Harel assigned Magen-Halevi and Mossad officer Yehudit Nessyahu to locate Yossele Schumacher, who had been abducted by his Haredi Orthodox Jewish grandparents.

[3] Later in her career, she was involved in Operation Wrath of God, the Mossad's retaliation campaign after the 1972 Munich massacre.

[3] She was publicly identified by the first letter of her name in a profile run by Yediot Ahronot as part of Israel's newspaper wars of the 1990s.