Eleven rainwater samples were collected in the Western Mediterranean region in clean conditions in order to study the partitioning of zinc between soluble and insoluble forms. The pH of the rainwater sampled ranges between 4 and 7; the high values of pH resulting from the neutralization of acidic species by the calcium carbonate present in desertic dusts. The soluble zinc ranged between 15 and 99% of the total zinc; the higher percentage are observed for the lower pH, and the lower percentage for the higher pH. This variable solubility can be explained by an adsorption-desorption equilibrium which is highly sensitive to the value of pH in rainwater. ¿ American Geophysical Union 1988