To the purpose of evaluating the effect of deformation on the microstructure, aluminum structures were analyzed on tensile strained samples extended to 25% elongation. In the substructure of these deformed samples linear slip patterns were observed, generally confined to the bulk of the grain. In order to study the crystallographic aspect of these slip patterns, two methods were applied based on orientation contrast microscopy (EBSD). The first method is the statistical analysis of stereological nature, which allows us to determine the incidence of certain crystallographic planes with the slip patterns. In other to corroborate the statistical method, also a 3D analysis was carried out on two perpendicular planes of observation (TD and ND sections). The results of both methods were in a very good agreement. It was found that the linear features are predominantly parallel to the {111} crystal planes, although the frequency of {111} planes was not exclusive; also other crystal planes such as {112} and {110} are involved. These observations give a stronger statistical basis for similar observations earlier made by TEM on much smaller fields of observation.