From 1981 to 1982, he spent time in Washington, D.C., as the CBS News State Department correspondent. From 1982 to 1987, Simon served as a New York-based CBS News national correspondent. In 1987, Simon was named the CBS News Chief Middle Eastern correspondent.
During the opening days of the Gulf War in January 1991, Simon and his CBS News team were captured by Iraqi forces and spent 40 days in Iraqi prisons; he later chronicled the experience in the book Forty Days.
In 1996, Simon joined 60 Minutes as a correspondent, and in 1998, he was named a 60 Minutes II correspondent. Notable stories he has done in recent years include the first profile of the so-called Lost Boys of Sudan and an exclusive interview with Iraqi Shiite insurgency leader Muqtada al-Sadr. He currently serves as the senior foreign correspondent on 60 Minutes.
In April 2012, 60 Minutes aired a piece on the plight of Christians in Israel, for which Simon was the correspondent.Michael Oren, the Israeli Ambassador to the United States, attempted to influence the segment by contacting CBS news and calling the piece a hatchet job.  As a result, Simon castigated Oren during an interview that was included with the piece.