A recent outbreak of measles in Morecambe accounted for nearly half the cases reported across the county, said the Health Protection Agency.
More than 80 measles cases have been reported in Lancashire so far this year – compared to just six in the whole of 2011.
The Health Protection Agency said it was unable to break the figure down for each district, but a recent outbreak in Morecambe was thought to account for at least 35 cases.
There were 94 confirmed cases in Lancashire in 2012, with 84 so far this year.
Kate Brierley, a consultant nurse at the Cumbria and Lancashire Health Protection Unit, said: “There’s a lot of measles around at present.
“Measles can be extremely unpleasant. In rare cases, people die. The best defence against it is MMR vaccine. We are advising parents to ensure children are up-to-date.”