A stunning result, which should put pressure on David Cameron to do the same for England - an election promise, in fact.
It's difficult to see how Cameron could not follow the Welsh example, given its success. Similar moves are now being planned by Scotland and Northern Ireland. However, across the UK, the number of carrier bags being used by supermarket shoppers climbed by 5.4% in 2011, according to the Government's own waste body WRAP.
Ban the bag
To put that in perspective, that's eight billion single-use throwaway plastic bags released into the environment. Many of these bags end up in rivers damaging bird and plant life - not to mention blowing around UK streets - and can take up to 1,000 years to fully break down.
How to explain the rise in use? The British Retail Consortium says that the on-going squeeze on people's disposable incomes means families are increasingly doing several smaller grocery shops during the week rather than one big trip, plus there is a switch away from going by car in favour of public transport.
Blame Osborne?"For both of these reasons consumers are less likely to have reusable bags with them and are therefore making slightly greater use of the bags made available by some retailers."
Responding to the new Welsh results, the BRC said any legislation "should be as similar as possible to what's in place in Wales and we are already working with other governments as they develop their plans."
So far, introducing a ban in England has backing from the Department for Environment, Food and Rural Affairs, but George Osborne and the Treasury are not keen, it's thought. The Treasury was not available to comment when contacted.