Yes there is one disadvantage. As the account is held in Rupees, if it depreciates you will lose. Imagine you had opened a NRE Fixed Deposit account with an inward remittance of US $100 with the intention of taking back your money in dollars when the deposit matures. If the Rupee /Dollar exchange rate at that time was 42.50, your account would have been credited with Rs. 4250. If, when the deposit matures, with the exchange rate at Rs. 43.50 to the dollar, your deposit amount will get you only $ 97.70.