Symmetrically oriented bicrystals of pure Al(99.998%) have been deformed in channel-die compression up to strains of similar to 1.5 to correlate the dislocation substructures and the slip system distributions. The study has focused on structure development in (100)< 001 >/{110}< 001 > (cube/Goss)-oriented bicrystals with the grain boundary situated parallel to the compression plane. Both orientations have the same nominal Taylor factor and deform macroscopically by the same amount but have stable (Goss) and unstable (cube) micro-deformation behavior. The character of the deformation substructure was determined by systematic local orientation measurements using high resolution EBSD in a SEM-FEG scanning electron microscope and also by transmission electron microscopy (TEM) and the CBED technique at specific locations. The bicrystal deformation analysis shows that the microtexture evolution within neighboring grains is quite different. Very strong deformation banding is observed within crystallites with the unstable orientation, i.e. cube-oriented grain forms classical deformation bands of slightly and strongly dislocated areas. The Goss-oriented grains within bicrystals are more stable under plane strain conditions and do not show any tendency to strain inhomogeneties except for the zone near the grain boundary.