The two-page ad stated: "What burgers have taught us", and went on: "The problem we've had with some of our meat lately is about more than burgers and bolognese. It's about some of the ways we get meat to your dinner table. It's about the whole food industry. And it has made us realise, we really do need to make it better."
Two people, one an independent butcher, complained that the ad implied there were issues with meat standards across the whole food industry and unfairly denigrated suppliers who had not been involved in the supply of mislabelled products.
Tesco said it accepted that not everyone in the food industry had been implicated in the selling of horsemeat, adding that there was no reference to any other producer, retailer or supplier.
It said it had "not attempted to shift or share the blame for the issues that Tesco faced", but the meat contamination problem they and others had encountered was due to systemic failings in the food supply chain which had serious consequences for Tesco.
It said: "Because the ad implied that all retailers and suppliers were likely to have sold products contaminated with horsemeat, and because relatively few instances of contamination had been identified at the time the ad appeared, we concluded the ad was misleading."
However it ruled that the ad was not denigratory because it did not name another product or marketer.
It ruled that the ad must not appear again in its current form.
A Tesco spokesman said: "We are disappointed with this decision, but accept that the ASA has taken a very literal view of the wording in the advert.
"We think our customers understood that our aim with the advert was to set out the action we had taken in relation to the horsemeat crisis and to acknowledge the fact the issue had serious consequences not just for Tesco, but for the whole of the food industry."