The frequency-dependent shear-wave quality factor (Q_\beta(f )) and site amplification are computed for the seismically and tectonically active Garhwal Himalaya. The inversion technique of strong motion data is applied to obtain Q_\beta(f ) and site effect at each recording station. The strong motion data of 82 earthquakes recorded in the Garhwal region is used for the present inversion algorithm. The comparison of site effects obtained by the present inversion scheme and well developed H/V technique (H/V is the ratio of Fourier spectra horizontal to vertical components) shows that site effects computed through the inversion technique have close resemblance with these estimates from the H/V technique. Both horizontal components are used to establish the frequency-dependent Q_\beta(f ) relations at each station. The values of ‘Q_o’ and ‘n’ at different stations vary from 92 to 112 and 0.9 to 1.1, respectively. The close resemblance of obtained Q_\beta(f ) relations at different stations suggest, the presence of almost similar type of lithology, i.e., hard rock at these stations. A regional quality factor relationship of form, Q_\beta(f ) = (102 ± 3.9)f^(1.0±0.1) is established for the Garhwal Himalaya based on modelled Q_\beta values of each station. This relationship reveals low Q_o value (${\le}$200) and high n value (${\ge}$0.8) for the Garhwal Himalaya, which correspond to tectonically and seismically active region.

$\bf{Highlights}$

$\bullet$ The frequency-dependent shear-wave quality factor and site amplification are computed simultaneously for the Garhwal region, NW Himalaya.

$\bullet$ A regional quality factor relationship of form, Qβ(f) = (102 ± 3.9)f(1.0±0.1) is established for the Garhwal Himalaya.

$\bullet$ The acceleration records corrected from the obtained site effect are used to develop attenuation relations at each recording station.

$\bullet$ The close resemblance of obtained Qβ(f) relations and the geology has been observed for the study region.