The number of cars sold last month compared to the same period last was down 35%, due in large part to the end of the scrappage scheme.
However, if viewed on an annual basis car sales are actually up by 10% compared to this time last year.
Diesel cars accounted for over 70% of new cars sold.
Alan Nolan from the Society of the Irish Motor Industry said the figures show that scrappage was a major help to boosting car sales.
The top-selling car makes are Toyota, Volkswagen and Ford. The best-selling models are the Ford Focus, Volkswagen Golf and Toyota Avensis.