Elbrus Kargiyev and Semyon Grigoryev gave their credentials to South Ossetian President Eduard Kokoity and Abkhazian leader Sergei Bagapsh.
Russia recognized Abkhazia and South Ossetia as independent states on August 26 after a five-day war with Georgia, which launched an attack on South Ossetia to try and regain control of the region.
On September 9, diplomatic ties were established between the states. In late October, Russian President Dmitry Medvedev appointed Kargiyev and Grigoryev ambassadors.
Kokoity and Bagapsh thanked the Russian authorities for the assistance given to the republics in all areas.
The two Georgian breakaway republics have had de facto independence since they broke away from Georgia in bloody post-Soviet conflicts in the early 1990s.