Only one in five travellers who use mobile internet services abroad think network operators charge fairly for them, according to a survey released by the European Commission (EC) on Monday.
Some 72% limit their roaming calls because of high charges, even though most know that the EC has forced prices down since 2006, researchers found.
The EC is reviewing roaming rules and costs and is due to report in June. Under the EC's Digital Agenda timetable, the cost of roaming locally and abroad in the EU should be the same by 2015.
Digital Agenda boss and EC vice-president Neelie Kroes warned telecom companies to listen to their customers. "Consumers feel there is still much room for improvement, particularly for data roaming," she said.
The survey shows that more people are using their mobiles while travelling in the EU than four years ago. Despite a 13% fall in travel between 2006 and 2010, travellers report making 32% more calls, receiving 31% more calls and texting 43% more since 2006, researchers said.
They found men are more likely to make voice calls (57%) while women prefer to send text messages (56%).
Young people are now significantly more likely to use roaming services compared to 2006 figures. Voice calls were up 43% with calls received up 42% and texting up 51%.
Almost a third of retired people and 15% of 25-39 year olds do not use their mobile phones abroad at all, researchers said.
Six out of 10 frequent travellers were aware that roaming prices decreased following the EU's intervention, but felt they were still too high. This led around one in five mobile users to cut their use of roaming services in the past four years. Eighty per cent of Swedes, 72% of Italians and 57% of Greeks are using roaming voice services less because of cost concerns.
The survey found 10% of travellers were surfing websites or downloading data while abroad. Lithuanians (17%) and Spaniards (15%) led the data roaming usage, but Hungarians (2%) and Germans (4%) were thriftier.