India's forex reserves dropped by $3.47 billion to $667.39 billion for the week ended July 26, according to the RBI data released on Friday.
In the previous reporting week, the kitty had jumped by $4 billion to an all-time high of $670.86 billion.
For the week ended July 26, foreign currency assets, a major component of the reserves, decreased by $1.17 billion to $586.88 billion, the data showed.
Expressed in dollar terms, the foreign currency assets include the effect of appreciation or depreciation of non-US units like the euro, pound and yen held in the foreign exchange reserves.
Gold reserves decreased by $2.3 billion to $57.7 billion during the week, the data showed.
The Special Drawing Rights (SDRs) were down by $5 million to $18.20 billion.
India's reserve position with the IMF was up by $2 million to $4.61 billion in the reporting week.