A joint project by the National Food Agency Finland, the State Provincial Office and municipalities, found that some half of the products available had insufficient labelling.
The project looked at 1,700 items, including everyday foods and ethnic products.
In many cases the worst offender were products' ingredients list. Quantities of various ingredients were not displayed properly and labelling of additives was found inadequate.
Some goods featured poorly displayed best-before dates and storage instructions.
Bakery produce, ready-made meals and ethnic products were amongst those that had the most inadequate labelling.
On the other hand, breakfast cereals and frozen foods had the clearest information.
Finnish-language information was displayed well in everyday foods, but facts in Swedish was poorly displayed on many products.
Half of imported ethnic products did not feature adequate information in Finnish.