The company had sold 14,378 units in the corresponding month previous year, Toyota Kirloskar Motor (TKM) said in a statement.
Sales in the domestic market stood at 10,648 units in December, down 11.78 per cent from 12,071 units in the year-ago period, it added.
During the month, the company exported 1,974 units of Etios, it said.
Commenting on sales performance, TKM Deputy Managing Director and Chief Operating Officer, Marketing and Commercial Sandeep Singh said: "The market sentiments do not seem to be improving. In the last few months, we have made our best efforts to control inventory both at TKM and at our dealers end.