Malta joined the EU in May 2004 and subsequently adopted the EURO as its official currency in January 2008. The now defunct Maltese Lira was equivalent to 2.3294 EUR (or 1 EUR = 0.4293 MTL)
All major currencies are accepted in local banks and if entering Malta with foreign currency, it is advisable to visit a commercial bank for the best exchange rates. Shops in tourist resorts do accept foreign currency, such as British Sterling or US Dollars, but exchange rates are unsurprisingly not as good as those found in commercial banks.
All major credit cards, especially VISA and Mastercard, are accepted in the majority of Maltese shops, restaurants and other commercial entities.