One of the supermarkets is located in Mangalia, on Romania's Black Sea coast, and has a retail area of 857 square metres, the company said in a statement.
The other store, in the southwestern town of Slatina, has a 918 square-metre retail area.
Billa Romania will expand its network to 70 stores following these openings.
Billa, part of Germany's REWE Group, plans to end 2012 with 71 stores in Romania, Romanian news daily Ziarul Financiar (www.zf.ro) reported in September.