This paper reviews the major results concerning the sol‐gel transition of a large variety of systems, including polymeric and colloidal solutions, whose process of gelation has been analyzed in the frame of the percolation model. I first recall the basic ideas of the model and the predictions regarding the main, characteristic and experimentally accessible, parameters. Among them, emphasis is placed on the rheological measurements, but I also discuss the possibilities of other techniques (like dynamic light scattering or electron microscopy) in order, either to investigate the kinetics of network growth, or the three‐dimensional supramolecular structure of fully matured gels.