Shops selling sweets, including newsagents and garage forecourt stores, have been given a warning that they must display prices.
Following a six-month nationwide campaign, director of consumer affairs Carmel Foley has threatened to take legal action against confectioners who do not obey retail rules.
"Sweet and chocolate retailers are not above the law. They must display their prices like the rest of the retail sector," Ms Foley said.
A survey carried out in June by consumer affairs officers revealed newsagents outside of Dublin were the worst offenders with a lowly compliance rate of 37 per cent. Those in the capital also performed poorly at 54 per cent.
Garage forecourts in rural areas had a rate of 43 per cent. Supermarkets had the highest compliance rates.
A follow-up survey in October showed overall compliance had jumped from 59 per cent to 92 per cent.
Garage forecourts remained the worst offenders, with supermarkets again coming out the best.
Ms Foley has written to 2,300 shop owners informing them of their obligations and the rules they must abide by.
"More work needs to be done to bring compliance by the garage forecourt sector up to the levels achieved by the other types of sweet and chocolate sales outlets.
"I will be concentrating on this sector in the coming months. If they fail to take their obligations to consumers seriously, then I will have no hesitation in bringing them before the courts."