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More than 340 earthquakes recorded by IGUT (Institute of Geophysics, University of Tehran) short period stations from 1996 to 2004 were analyzed to estimate the S-coda attenuation in Alborz region, the northern part of the Alpine–Himalayan orogen in western Asia, and in Central Iran which is the foreland of this orogen. Two anomalous high attenuation areas in Central Iran are recognized around the stations LAS and RAZ. The average frequency relation for Central Iran excluding the values of these two stations is Qc=94±2 f 0.97±0.12. To investigate the attenuation variation with depth, Qc value was calculated for fourteen lapse times for two datasets having epicentral distance range in each area. It is observed that Qc increases with depth. However, the rate of increase of Qc with depth is not uniform in our study area. Beneath Central Iran rate of increase of Qc is greater at depths less than 100 km compared to that at larger depths indicating the existence of a high attenuation anomalous structure under lithosphere of Central Iran. In addition, below ~180 km, the Qc value does not vary much with depth under both study areas indicating presence of a transparent mantle under them.