Non-essential retailers have re-opened their doors for after being closed for six weeks.
A number of them stayed open 24 hours to facilitate demand.
Newstalk reporter Kacey O'Riordan was on the ground, queueing, on Tuesday night at Penneys in Blanchardstown.
She told Newstalk Breakfast the crowds were still there well past midnight.
"I arrived around 10 o'clock and there was actually hundreds of people queueing at that stage.
"I stayed for a few hours and the queue shortened a bit, but even at 12.15am I counted 105 people queueing outside alone - because even after queueing outside, you'd more of a queue to go once you'd got your foot in the door".
She said she joined the queue just before 1.00am, and it was 40 minutes until she got through the shop doors.
"After I got in the door, I walked around for a few minutes and I left.
"And at 1:35am I came back out and there was actually no one waiting - so maybe that's the saturation point for people".
"The queue outside was OK, but inside the centre - that queue in the doors before you finally got into Penneys - was not good.
"We really were on top of each other, and people were also very unimpressed that a lot of stuff was sold out".
One woman said: "I thought I was going to beat the crowds, took me about 20 minutes to get in - it's carnage in there.
"People climbing over each other trying to get at stuff, shelves emptied, stuff pulled out on the floor.
"I would say at least a third of people either aren't wearing masks or have them down under their nose or under their chin".
In a statement, Penneys said "nothing matters more to them" than the health and well-being of employees and customers, and strict social distancing rules have been implemented across their stores.
A spokesperson said: "Our customers are responding well to these measures, and understandably it has meant there have been some queues outside the stores. We have dedicated Penneys colleagues and additional security staff helping with queues, limiting the number of customers allowed in stores and asking every customer to wear a mask upon entering the store.
"Additionally, we have redesigned the layout of our stores to allow for more space between people and reconfigured the queueing system at our till points to allow for social distancing. We are grateful to our customers for following the guidelines.”