Abstract The anelastic attenuation of seismic waves, as expressed by the Q-factor, is compared for two regions: between the Mid-Atlantic Ridge and the seismic station Hamburg F.R.G., and the Hindu Kush and the same station. Eight earthquakes in the distance range 44.7 ° to 59.1 ° were chosen. The spectral ratios of short-period ScS- and ScP-, as well as PcS- and PcP-phases were computed, and used to estimate the differential effect of attenuation on P- and S-waves. Assuming the ratio of Q-factors for P- and for S-waves to be Q α Q β = 1.75 , Q β -values of 161 for the western part and of 324 for the eastern part of Europe are found. The pronounced difference of the average Q-values for the earth's mantle is interpreted as being related to a regional variation of the anelasticity in the lowermost mantle, below 2200 km. In the frequency band 0.1 to 0.6 Hz the Q-factors are likely to be frequency-independent.