The occurrence of dislocation sites along grain boundaries is shown by transmission electron microscopy. Small thin sections of aluminum for these studies were obtained by electrolytic oxidation, with subsequent dissolution of the oxide. Dislocation sites along grain fragments in cold worked aluminum have been observed which, by Cottrell's formula, indicate grain orientation differences greater than 2° of arc. This method of examination makes possible the observation and analysis of dislocations in metals where boundaries are at other than extremely low angles of crystal misorientations. Also, it has been found useful for following the movement of dislocations within grains of the material and their migration to grain boundaries.