Method for estimating the number of people present within a given geographical area, with at least a portion of the people being equipped with cellular terminals that communicate according to at least two predefined communication standards. The method includes the steps of: (a) using a traffic analysis on the one or more networks present in the predefined area, carried out using at least one traffic analyzer located in the area and with a range chosen according to the area to be covered, detecting, for each of the standards, at least one indicator that represents the activity of a terminal on the network(s) and operating according to at least the same standard, (b) deducing the indicators thus detected, counting the number of cellular terminals present in the area, (c) estimating the number of people present in the area, using at least one law of correlation between the number of cellular terminals thus counted and the corresponding number of people present in the area.