This study concerns the predicted performance of multifrequency ground-based radiometers in estimating atmospheric moisture and the corresponding attenuation and wet path delay on an Earth-space path. The analysis of the performance is based on a numerical simulation using possible combinations of radiometric channels at 10 microwave frequencies below 100 GHz. We first discuss the accuracy of retrievals of both integrated atmospheric vapor and cloud liquid from noisy raidometric measurements carried out at two frequencies and investigate the improvement attainable by using more than two radiometric channels. Then we focus the problem of predicting attentuation and wet path delay at several frequencies in the millimeter wave range for a vertical Earth-space path from radiometric data. Examples of possible combinations of two and three frequencies are presented, ranked according to their capability, first in retrieving vapor and liquid, then in predicting attenuation and wet path delay for two different climatologies. ¿ American Geophysical Union 1993