Seismic activity around Pong, Pandoh, Bhakra and Salal dams in Northwest Himalayas has been reviewed in relation to filling of the reser voirs. The pattern of seismic activity around Bhatsa and Koyna regions has also been examined in detail. It has been found that no significant increase in seismic activity has occurred in and ar ound the dams in Northwest Himalayas so far. The seismic activity around Koyna and Bhatsa dams could be examined in terms of modified as- perity models of Kanamori (1981). The model proposed for the Koyла seismic activity after the main shock when applied to Bhatsa region predicted successfully the recent earthquake of 2 June 1990 (м 4.0). According to this hypothesis the magnitude of the largest earthquake in these two regions would not exceed that of the largest aftershock which had occurred after the main earthquake and would be gradually decreasing with time in magnitude at progressively larger recurrence interval.