Nowadays, satellite images have been used for many applications intensively. Using of the digital satellite images in relevant approaches may give more accurate ideas about the researched fields. Besides, different methods could be used for derivation of maps from relevant digital data in many scientific disciplines. One of these methods is to use satellite images. The most important reason of using the maps, which are derived from satellite images, is accuracy of data. To obtain maps from satellite images or use satellite images as map, the satellite images required certain rectification. For a rectification process, ground control points are plotted in field. In the present study, the most suitable ground control point sizes were investigated for multi-spectral images from IKONOS satellite of one-meter resolution. The present study showed that the most suitable size of ground control point was 2.5 m diameter points. © 2004 International Society for Photogrammetry and Remote Sensing. All rights reserved.