This work presents the results of an experimental study concerning the fluidized bed coating of spherical solid particles by injection of an aqueous solution of lactose. The objective was to study the influence of the wetting parameters on the coating efficiency and the growth rate. Two methods were applied to modify the wetting parameters of the solid-liquid couples used. The first one consisted of the addition of a determined quantity of a surface agent into the coating liquid and the second involved the modification of the surface of solid particles by chemical treatment, i.e., silanization. The former allows the alteration of the superficial tension of the liquid but also affects the liquid-solid contact angle, whereas the latter increases the contact angle without changing any other property of the solid or liquid. The results showed that the coating efficiency has a tendency to decrease by increasing the contact angle, 0, at constant liquid surface tension, gamma(Lv). However, the effect of the liquid surface tension is less obvious mainly because this parameter cannot be modified without affecting the contact angle. Although the coating efficiency was found to increase with adhesion energy (gamma(LV)(1+cos theta)) it has been established that the relationship between these two parameters is not linear. Additional considerations based on geometrical features with regard to the spreading of liquid droplets onto the solids surface, permit the explanation and linearization of the variations of the coating efficiency. In addition, for contact angles higher than 90 degrees, a drastic decrease in the efficiency was observed. This phenomenon was explained by rebound phenomena which take place during droplet-substrate collisions. The variations in the growth rate according to the contact angle and the liquid surface tension seem controversial. Nevertheless, the variation of this parameter seems to be directly related to interparticulate forces resulting from liquid bridges.