Abstract : A method is described for the automatic calibration of the successive operational Meteosat sensors in the visible range since 1985. As a starting point, the absolute vicarious calibration for only one image in the whole time-series is needed, which can be provided by previous published works. The automatic method performs on a daily basis and is based on a statistical analysis of two images, one when the Sun illuminates the entire field of view of Meteosat, the other during night-time. This approach does not require any information about atmospheric and surface parameters, and therefore can be easily performed either on archived data, or in quasi-real time when receiving the images. Our results are fully consistent with previous studies. Several tests have been performed to validate the method and check its robustness and reliability.