Figures from the Central Statistics Office show that foreign workers accounted for one in eight workers in the State at the time of the Census last year.
The hotels and restaurants sector had the highest proportion - almost 32% - followed by business activities at 16.2%. This category includes computer work and industrial cleaning.
The figures, which give the main socio-economic aspects of the Census findings, show that the labour force grew by 308,500 or 17% between 2002 and 2006, with the numbers in work growing by 288,400.
Limerick City had the highest unemployment rate at 14.6%, with Dun Laoghaire-Rathdown lowest at 5.4%.
Other Census figures show that 828,000 households (56.6%) had a PC, with 683,000 having internet access. 292,000 had a broadband connection. Dublin had the highest rates, with Limerick City, Longford and Cork City lowest.
