Sales of food, drinks and tobacco were down 1.8% in November from the previous month in data adjusted for the number of working days and seasonal factors.
Fuel sales rose 0.6% on the month, while non-food product sales were unchanged from October.
In annual terms, adjusted retail sales advanced 1.9% in November, fueled by increases in non-food product and fuel sales by 7.2% and 4.6% respectively, INS said.
Food sales fell 4.9% on the year in November.
In January through November, Romanian adjusted retail sales declined 4% on the year, due to falling consumption in all sectors.
Food sales fell 7.5% on the year in the first eleven months, while fuel sales were down 3.2%. Non-food sales inched down 0.8%, the data showed.