The rupee depreciated by 21 paise to 73.13 against the US dollar in opening trade on Thursday tracking muted opening in domestic equities and strengthening American currency.
At the interbank forex market, the domestic unit opened at 73.13 against the US dollar, registering a fall of 21 paise over its previous close.
On Wednesday, the rupee had settled at 72.92 against the American currency.
Meanwhile, the dollar index, which gauges the greenback's strength against a basket of six currencies, rose 0.12 per cent to 90.75.
"The US Dollar Index has started higher this Thursday morning in Asian trade amid safe haven appeal for the greenback amid weakening risk appetite," Reliance Securities said in a research note.
Asian currencies were weak against the greenback and could weigh on sentiments, the note added.
Markets will look to cues from US GDP data and a weaker than expected numbers will push more investors towards the US dollar and vice versa, the note said.
The US Federal Reserve has decided to stick to its dovish stance and left key overnight interest rate near zero to maintain monetary support until there is a stronger rebound from the pandemic-triggered recession.
On the domestic equity market front, the 30-share BSE benchmark Sensex was trading 336.05 points lower at 47,073.88 and the broader NSE Nifty was down 95.60 points at 13,871.90.
Foreign institutional investors were net sellers in the capital market as they offloaded shares worth Rs 1,688.22 crore on a net basis on Wednesday, according to exchange data.
Brent crude futures, the global oil benchmark, fell 0.61 per cent to USD 55.47 per barrel.