The rate of adsorption of positively charged poly(propylene imine) dendrimers on glass, an oppositely charged surface, has been studied as a function of generation and charge (by systematic adjustment of pH and ionic strength) using scanning angle reflectometry and an impinging-jet cell. A comparison of the mass transport conditions for this geometry and the bulk long-time self-diffusion coefficient obtained from pulsed field gradient NMR experiments shows that a sticking probability of the order of 3% is needed to relate the diffusion toward the surface with the long-time self-diffusion in the bulk. The adsorption kinetics were mostly diffusion/convection controlled with a linear dependence on the bulk concentrations up to 10 mg/L at pH 7 and in 0.1 M NaCl. At higher bulk concentrations there is a drop in concentration dependence into a 1/3 power law dependence. This crossover concentration shifts to higher concentrations with decreasing pH (increasing dendrimer charge).