Mahindra & Mahindra (M&M) had sold 43,460 units in the same month last year, the company said in a statement.
M&M's domestic sales stood at 35,499 units last month as against 42,104 a year earlier, down 15.68 per cent.
Sales of passenger vehicles, including Scorpio, XUV 5OO, Xylo, Bolero and Verito, stood at 18,085 units compared with 22,244 units in May 2013, down 18.69 per cent.
Four-wheel commercial vehicle sales declined 13.55 per cent to 12,836 units as against 14,848 units, it said.
Exports rose 74.77 per cent to 2,370 units from 1,356 units earlier.
"Auto sales continue to remain subdued for many players, at the back of yet another challenging month for the industry," M&M Chief Executive (Automotive Division) Pravin Shah said.
He said: "Post the electoral mandate, we expect to see improved sentiment resulting in a better economic situation which we hope will lead to a gradual increase in demand."