After he retired from playing, Keosseian became a manager and has led several clubs, including Uruguayan side C.A.
Keosseian appeared for Aucas as a player, and would later manage in Ecuador with El Nacional.
[1] Before Keosseian led the "Rojos" to the 2010 Guatemalan Clausura championship.
[citation needed] In the afternoon of 21 June 2010 he communicated to csD Municipal that he would be the new manager of C.A.
He suggested to Bella Vista of Montevideo, hire Egidio Arevalo Rios, Uruguayan midfielder of national team.