Although riming has been demonstrated to influence precipitation chemistry, its relative importance as a mechanism for the transfer of trace species into snow is not well known. To overcome the qualitative measure of riming in past studies, the mass fraction of snow originating from accreted cloud droplets (rimed mass fraction) is estimated indirectly in this study from replicas of collected snow crystals and flakes. The rimed mass fraction is then compared with the concentrations of various ionic trace species in collected snow and cloud water samples at a prealpine site in Switzerland from 10 case studies. The ratio of the precipitation to the cloud water concentration for a given ion, which indicates the transfer efficiency of the species from clouds to snow, was found to be correlated weakly to the rimed mass fraction for all sample periods investigated. However, much of the variability in the relationship came from sampling periods when the precipitation intensity was low. The relative importance of riming and other scavenging processes was estimated from the sample set, although this estimate is complicated by differences in concentration between cloud droplets collected by snow and those sampled at the site and by case to case variability. Under conditions of higher precipitation intensities, riming appear to be the dominant transfer mechanism for the incorporation of the major ionic species into snow. ¿ American Geophysical Union 1995