Most people visit the North either for business or to see a friend or relation, whereas most go to the Republic for holidays, the report shows.
Only 18 per cent of the 1.6 million visitors to Northern Ireland in 1999 had gone to take a holiday compared to 54 per cent of the 6.1 million visitors to the Republic.
The main reasons given for visiting Northern Ireland were business (30 per cent) and seeing a friend or relative (41 per cent). In the Republic, only 16 per cent of visitors said business was their primary reason for coming and 24 per cent said seeing a friend or relative.