The project to transform Lansdowne Road into a 50,000 all-seater stadium has been given planning permission by Dublin City Council.
The redevelopment of the famous old venue at Ballsbridge is expected to start in 2007 and is likely to take two years to complete.
Permission was granted after a long period of consultation with local residents who had expressed concerns.
A number of conditions have been attached to the planning approval.
An Irish RFU statement welcomed the aproval but conceded there was still some way to go in the process.