We have investigated the effect of magnetic processing on orientation of gold nanowires (AuNWs) using a strong magnetic field. The results in the extinction spectra due to surface plasmon and SEM images in the presence of magnetic processing (10 T) showed that the long axes of AuNWs in side-by-side aggregation of AuNWs were oriented perpendicular to the magnetic field. On the other hand, in the absence of magnetic processing, random orientation of the side-by-side aggregation of AuNWs was observed. The magnetic orientation of the aggregation is most likely attributable to the anisotropy in the magnetic susceptibilities of the pristine AuNWs.