Transmission electron microscope observations have been made of dislocations in Ga0·7Al0·3As after indentation of (001) surfaces at room temperature. Using two-beam imaging, in bright-field and weak-beam imaging, dissociated dislocations with extended stacking faults were observed both in the [110] and [110] directions. This is different from GaAs in which dissociated dislocations are seen in only one of these directions. These results are compared with published work on indented GaAs and considered in the light of possible mechanisms.