Experimental determinations of apparent viscosity were used to investigate the rheological behaviour of easy-to-disperse (ETD) Carbopol 2001, 2020 and 2050 hydrogels, involving different polymer concentrations, degrees of neutralization, agitation times and shear rates. Mathematical expressions were obtained, based on the power law, to allow calculation of the viscosity of each system, for the different variables studied. These equations proved valid within the 5.5-7.5 pH range, i.e., the pH interval of greatest interest in pharmaceutics and cosmetics. The rheological behaviours of the three types of ETD hydrogels were investigated comparatively and with respect to Carbopol 940, i.e., one of the most widely utilized hydrogels.