Residents accounted for 76.7% of total arrivals at accommodation establishments in January to June, while foreigners made up for the reminder 23.3%.
The large majority of foreign visitors (94.3%) came from Europe, the data showed.
Numbers of Romanian tourists traveling abroad fell 0.6% compared with the first half of 2010.
In June alone, tourist arrivals increased by 17.6% on the year, while overnight accommodations were up 3%.