Ferroelastic domain reorientation in polycrystalline rhombohedral LaCoO3 has been demonstrated by backscatter electron (BSE) imaging and electron backscatter diffraction (EBSD) combined with in situ compression testing. Four different domain orientations were confirmed in line with expectation from crystallography. During in situ compression reorientation of domains were observed favoring domains with the c-axis close to perpendicular to the stress field. In situ compression combined with BSE/EBSD is shown to be an excellent tool for studying the influence of mechanical stress on grain/domain structure in polycrystalline ceramics.