Changes in the orientation of crystal axes of Al-0.8 wt% Si single crystals in the presence of two different particle sizes and inter-particle spacings were investigated during uniaxial compression. The orientation of crystal axes before and after deformation was precisely determined by the diffractometer method in the unit triangle of the stereographic projection. The reorientation of the compression axes after deformation was found to be influenced by particle size and initial orientation of the undeformed crystals. It was found that particle size also influenced the yield strength and work-hardening characteristics which was explained on the basis of Orowan stresses and solid-solution strengthening.