Abstract: Combustion-induced unsteady oscillations referred to as screech are suppressed in gas turbine combustors by a plurality (preferably two to six) of screech suppression members disposed in the premixers of the combustors. The screech suppression members are attached to the centerbody of the premixer and extend radially outward, nearly into contact with the inner surface of the premixer tube. The screech suppression members are uniformly spaced about the centerbody and are axially positioned at or near the end of the centerbody which is closest to the main combustion chamber. Alternatively, each screech suppression member can be attached to the inner surface of the premixer tube and extend radially inward nearly into contact with the centerbody. Possible shapes of the screech suppression members include a thick block, a thin rectangular plate, a triangular plate, a V-shaped member, and a cylindrical bar.