A state-of-the-art outpatients department will be the first completed phase in a €284m development at the Mater Hospital.
It will include the first hospital outpatients "self-registration" check-in service in the country and will be fully open within the next few weeks.
Once the outpatients department is up and running, priority will turn to a new emergency department, 12 new operating theatres, intensive care, radiology and single ensuite rooms, which are due for completion between July and December.
The new Mater adult hospital building will be the greenest and most technologically driven hospital in the country.
The roll-out of 120 one-bed ensuite rooms will play a significant role in fighting the spread of infection, and a spacious rooftop decked garden for patients, staff and visitors is also part of the plan.
Parking will be provided in a 444-space underground car-park. Hospital clinical director Prof Conor O'Keane said the development "will allow us to break free of the shackles of limited space as we will now have appropriately sized departments and waiting areas".
"It provides patients and staff with an environment reflective of the quality of care patients get at the Mater into the 21st century and beyond."
The Mater admits about 16,500 patients each year, including 13,000 emergencies. Staff at the hospital see about 40,000 day cases and treat in excess of 47,500 emergencies.
They also treat more than 220,000 outpatients at the hospital which is the national centre for cardiac surgery, heart and lung transplants, spinal injuries and life support services.
The new development, in conjunction with the National Clinical programmes, is aimed at reducing waiting times for theatre, outpatient and accident and emergency services.
The hospital development started in 2000 and involves the rebuilding of parts of the landmark hospital, which celebrated its 150th birthday last year.