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High resolution maps of seismic attenuation parameters in Taiwan have been obtained from a modified "Multiple Lapse Time Window Analysis" (MLTWA). At most of the stations in porous sedimentary and highly faulted areas in Taiwan, the conventional modeling of MLTWA based on the scalar theory of radiative transfer in a half‐space with isotropic scattering fails to explain the spatio‐temporal distribution of the whole S‐wave train. Using Monte Carlo simulations of wave transport, we demonstrate that this anomalous energy distribution in the coda may be modeled by multiple anisotropic scattering of seismic waves. In addition to the scattering quality factor Qsc ${Q}_{sc}$, we introduce a parameter g $g$ (independent of Qsc ${Q}_{sc}$) which determines the angular redistribution of energy upon scattering (scattering anisotropy). We inverted the attenuation parameters Qsc−1 ${Q}_{sc}^{-1}$, Qi−1 ${Q}_{i}^{-1}$ and g in three frequency bands (1–2, 2–4, and 4–8 Hz). Overall, Taiwan is more attenuating than most orogens with a mean effective scattering loss Qsc∗−1=Qsc−1(1−g) ${\left({Q}_{sc}^{\ast }\right)}^{-1}={Q}_{sc}^{-1}(1-g)$ and a mean intrinsic absorption Qi−1 ${Q}_{i}^{-1}$ of 2.5 × 10−3 and 9 × 10−3 at 1.5 Hz, respectively. Scattering loss Qsc∗−1 ${\left({Q}_{sc}^{\ast }\right)}^{-1}$ varies over more than one order of magnitude across Taiwan while absorption variations reach approximately 30%. The more attenuating zones are the Coastal Range and the Coastal Plain where scattering dominates over absorption at low frequency, and inversely at high frequency. These regions are also characterized by strong backscattering (g $g$ < −0.85) at 1.5 Hz and rather high VP/VS ${V}_{P}/{V}_{S}$ ratio. We propose that the observed strong back‐scattering at low frequency, related to large impedance fluctuations in the crust, is induced by the presence of fluids. Plain Language Summary: Seismic attenuation is a key parameter which controls the amplitude decay of ground motions with the distance from an earthquake. Scattering and absorption are the two mechanisms controlling attenuation. The former is caused by the presence of small‐scale geological heterogeneities in earth's crust. The later is caused by anelastic processes related to fluids. The analysis of the distribution in space and time of the seismic energy allows us to separate the contribution of the two mechanisms. We implement a new propagation model which takes into account the nature of heterogeneities. This model has been used to map seismic attenuation across Taiwan. Overall, this orogen is more attenuating than most others worldwide. Spatial variations in scattering attenuation reach about one order of magnitude across the Island. By contrast, absorption variations are of the order of 30%. High tectonic or volcanic activity is correlated with strong scattering and absorption, low seismic wavespeeds and high velocity ratios between seismic compressional and shear waves. In the same areas, our model also reveals that seismic energy is strongly backscattered, hence tends to diffuse out more slowly from the source region. The combination of these observations may be indicative of a high concentration of fluids/melts. Key Points: We map crustal seismic attenuation parameters across Taiwan in the 1–8 Hz band with a spatial resolution of 30 kmScattering loss varies over more than one order of magnitude across Taiwan; variations of absorption are of the order of 30%Anomalous energy distribution in the coda observed in porous sedimentary and highly faulted areas is explained by the presence of fluids [ABSTRACT FROM AUTHOR]