Tourism body Failte Ireland has warned that the Republic must continue to be seen as offering excellent value for money.
On the back of increasing visitor numbers in the first four months of 2018, Failte Ireland chief executive Paul Kelly said its research is picking up a softening in the country's value for money ratings.
He suggested that if this trend continues, the Republic will be seen as an expensive destination for tourists and the work of recent years by the sector will be undone.
"It could take us years to reverse that perception," Mr Kelly said.
He also used the publication of visitor numbers from the Republic's Central Statistics Office to call for increased investment from both the public and private sector in all areas of tourism, from accommodation to infrastructure.
The Republic welcomed 2.8 million visitors in the first four months of 2018, up 7.3% on the same period in 2017.