Imported malaria infections have increased by 9% since last year, new figures show.
The statistics, published by Public Health England (PHE) for World Malaria Day show there were 1,501 confirmed cases in 2013, compared to 1,378 in 2012.
Most of the cases (79%) were caused by Plasomodium falciparum, a more severe form of malaria which is acquired in Africa.
The highest proportion of cases - as in previous years - is in travellers who are non-UK born and have visited family in their country of origin.
Dr Jane Jones, head of the PHE's travel and migrant health section, said: "The proportion of cases who have not taken appropriate antimalarials remains high.
"It’s important to stress that any partial protection people may have gained from being brought up in a country where malaria is common is quickly lost when living in the UK.”
Dr Jones said that health messages about the importance of antimalarials are "not reaching" the groups at risk.
Malaria, an almost completely preventable but potentially fatal disease, remains an important issue for UK travellers, PHE has stressed.
There is continuing evidence that those of African or Asian ethnicity who are non-UK born and going to visit family in their country of origin are at increased risk of malaria.
PHE recommends that those providing advice should engage with these population groups wherever possible, including using potential opportunities to talk about future travel plans outside a specific travel health consultation, such as during new patient checks or childhood immunisation appointments.