Trong worked as a member of the magazine's editing board between March 1989 and April 1990, and became deputy editor-in-chief from May 1990 to August 1991, and editor-in-chief in August 1991.

He was elected to the Communist Party of the Vietnam Central Committee (CPVCC) in January 1994, re-elected in June 1996, and became deputy secretary of the Hanoi Party Committee in October 1996, and member of the CPVCC's Political Bureau in December 1997.

Trong assumed secretary of the Hanoi Party Committee in January 2000, chairman of the Central Theoretical Council in 2001, member of the CPVCC in April 2001, and member of the Political Bureau in April 2006.

Trong acted as Chairman of the National Assembly from 2006 to 2011.

In January 2011, Trong was elected as General Secretary of the 11th CPVCC.