Romania’s currency is the “leu” (plural “lei”) (it means “lion” in Romanian). It is the descendant of a Dutch currency that was used in this area in the 17th century. 

1 leu = 100 bani (plural; singular: “ban”).

Given the trend of falling inflation, the national bank of Romania(BNR) decided to revalue the leu as of July 1st 2005. A new leu (RON = acronym for ROmanian New) equals 10000 old lei (ROL).

The old lei could still be used until the end of 2006, but is now no longer valid. The differences in design between the old and new lei are very small. The banknotes have the same colour (e.g.: the 10000 old lei bill is just as green as the new 1 leu bill) but the new bills are smaller than the old bills. Only the coins show significant differences but you should be fine as long as you keep the conversion rate between old and new lei’s in mind (10000 old = 1 new).

BNR has a table showing the exchange rates between the RON and the major currencies for the past 5 days here.

Romania plans to adopt the Euro at a future date, many years after EU accession. The planned date for Euro adoption was somewhere between 2011 and 2012 but the latest developments in the country suggest that a 2029 deadline is much more realistic.