The Indian rupee slumped 18 paise to 73.53 against the US dollar in opening trade on Tuesday tracking weak domestic equities and strong American currency.
Forex traders said concerns over rising COVID-19 cases also weighed on investors' sentiment.
At the interbank foreign exchange, the domestic unit opened lower at 73.47 against the dollar, and lost further ground and touched 73.53, registering a fall of 18 paise over its previous close.
On Monday, rupee had closed at 73.35 against the US dollar.
The domestic unit started on a weaker note against the dollar tracking decline in Asian shares and currencies on concerns over rising US inflation expectations, Reliance Securities said in a research note.
Most of the Asian currencies are trading weaker against the dollar and could weigh on sentiments, the note said, adding that markets will also await domestic IIP and CPI data this week.
Single day spike of 3,29,942 COVID-19 infections, 3,876 fatalities has pushed India's tally of cases to 2,29,92,517, and death toll to 2,49,992. Active COVID-19 cases in country recorded at 37,15,221, according to the Health Ministry.
In the equity market, the 30-share BSE Sensex was trading 336.74 points or 0.68 per cent lower at 49,165.67. Similarly, the broader NSE Nifty slipped 97.10 points or 0.65 per cent to 14,845.25.
Foreign institutional investors (FIIs) remained net buyers in the capital markets, as they purchased shares worth Rs 583.69 crore on Monday, as per provisional data.
The dollar index, which gauges the greenback's strength against a basket of six currencies, was trading higher by 0.03 per cent at 90.23.
Brent crude futures, the global oil benchmark, were down by 0.67 per cent to USD 67.86 per barrel.