He also served as Minister of the Presidency during the two governments of his brother, Óscar Arias Sánchez, from 1986 to 1990 and 2006 to 2010.

[1] Sánchez was elected municipal councilor of Heredia for the four-year term 1974–1978.

He achieved this victory even though he had not always been a member of the ranks of the National Liberation Party – as his brother Óscar Arias – because as a young man he sympathized with the presidential candidacy of José Joaquín Trejos, of the National Unification Party, who ruled from 1966 to 1970.

During his tenures as Minister, Sánchez played an important role as a government spokesman and in favor of CAFTA implementation laws.

In March 2009, Rodrigo Arias Sánchez declared himself in favor of a constitutional reform.