There was an almost 13% increase in the number of Irish people taking trips abroad in the first quarter of the year.
Up to 1.5m outbound trips were made in the first three months of 2016 - with the UK and Spain the most popular destinations.
Irish people spent an average of just over €1,200 on their trips abroad.
There was also an almost 20% increase in the amount of overnight breaks where people chose to stay in Ireland, after the CSO used an improved methodology which they say provides greater accuracy.
Patsy King, Statistician, Tourism and Travel Section, CSO said: "Analysis of the data showed that more older people were completing the HTS questionnaire and that younger age categories were under-represented.
"As a consequence, the CSO decided to review how the results are weighted by age group.
"Significantly, the revisions demonstrate that in fact about 20% more domestic trips are taken each year than was previously estimated. The new methodological changes, however, have a minimal effect on the estimate of outbound trips, which are calibrated to international passenger data."