Abstract <p>A frequency-dependent Lg attenuation model has been developed for North East India (NEI). The model has given a crustal quality factor for Lg (Q_o) of 197.2, and the power of frequency dependence (η) is 0.997. The peak value of attenuation is observed around 0.5 Hz, which aligns with Keiiti Aki’s 1980 experimental curves for tectonically active regions worldwide. The low value of Q_o and high η comply with the tectonically active and seismically hazardous regions of the world. Moreover, the extremely high value of (η) refers to the dominantly scattering mechanism of Lg wave attenuation. The study region is currently one of the highly tectonically active regions, which must have contributed significantly to the heterogeneities in the underlying crust, scattering Lg energy, and causing a high degree of attenuation. The impending seismic hazard in the NEI region is extremely high, and this Lg model can play a pivotal role in computing moment magnitude and developing reliable ground motion models for safe and resilient civil engineering practices.</p> Research highlights <p><UnorderedList Mark="Bullet"> <ItemContent> <p>A frequency-dependent Lg attenuation model has been developed for North East India (NEI)</p> </ItemContent> <ItemContent> <p>Scattering is the dominant Lg attenuation mechanism for NEI</p> </ItemContent> <ItemContent> <p>The region conforms to highly tectonically active and seismically hazardous regions of the world</p> </ItemContent> <ItemContent> <p>The extensive laterally heterogeneous crust contributes to the high scattering of Lg energy</p> </ItemContent> <ItemContent> <p>This Lg attenuation model will serve towards the computation of moment magnitude and reliable ground motion models for safe and resilient civil engineering practices</p> </ItemContent> </UnorderedList></p>