New figures from the Central Statistics Office show that consumer prices were 0.4% lower in February compared with the same time last year.
But consumer prices grew on a monthly basis for the fourth successive month in February, today's CSO figures show.
Year-on-year inflation has been negative since Covid-19 restrictions were first introduced almost 12 months ago.
Today's figures show that transport costs decreased by 2.7% on an annual basis in February on the back of lower air fares and lower prices for diesel and petrol.
But the CSO said this decrease was partially offset by higher prices for cars.
February also saw clothing and footwear prices falling by 6.8% from February 2020 due to sales.
Food and non-alcoholic beverages prices fell by 1.9% due to lower prices across a range of products such as meat, jam, honey, chocolate & confectionery and mineral waters, soft drinks, fruit and vegetable juices.
Furnishings and household equipment prices were also 2.7% lower in February.
Transport, clothing and footwear posted the largest monthly price increases among the main categories in February, the CSO added.
