The 2003 Altai earthquake, or 2003 Chuya earthquake, occurred on September 27 at 18:33:26 local time with a moment magnitude of 7.3 and a maximum Mercalli intensity of X (Extreme).

The epicenter of this oblique-slip shock was in Altai Republic, Russia near the borders of Mongolia, China, and Kazakhstan.

Three deaths and five injuries were reported and the total damage was listed as $10.6–33 million.

This earthquake had components of right-lateral strike-slip and reverse movement in a segmented fault zone which had not been previously recognized.

[3][4] Landslides affected the Kosh-Agachsky and Ust'-Ulagan Districts.