After graduating from the Basic Officer’s Course in Estonia, LTG Terras served as a Company Commander and as a Battalion Second in Command of the Kalev Single Infantry Battalion from 1992 to 1993.

Between 1993 and 1994 LTG Terras served as the commander of the Põhja Single Infantry Company. After graduating from the Bundeswehr University (Germany) he served as the commander of the Guard Battalion from 1998 to 2000. LTG Terras was appointed the Chief of Staff of the Defence League Headquarters in 2000. From 2001 to 2004 he served as the Estonian Defence Attaché in Germany and Poland.

Between 2005 and 2008 LTG Terras served as the Chief of the Analysis and Planning Department and as Chief of the Planning Section, Analysis and Planning Department in the Estonian Defence Forces Headquarters. In 2007, LTG Terras served in the NATO Training Mission - Iraq as Deputy Chief of Staff. LTG Riho Terras was confirmed on December 2008 as Permanent Secretary of the Estonian Ministry of Defence. Before taking up the position of the Permanent Secretary, he was Deputy Chief of Staff for Operations in the Estonian Defence Forces.

LTG Terras served as the Deputy Chief of Staff for Operations of the Estonian Defence forces from January 2011 to March 2011 and then continued his service as the Chief of Staff of the Estonian Defence Forces.

LTG Riho Terras was appointed the Chief of Defence on December 5th 2011.