The number of cases of mumps and measles in Surrey has seen a big increase, according to the Health Protection Agency (HPA).
Figures showed the number of people suffering from mumps went up from 7 in 2008 to 34 in 2009.
The number of cases of measles almost doubled from 25 to 46, in the same period.
Two doses of the MMR vaccine provide 99% protection against measles, mumps and rubella.
Health officials have urged parents to make sure their children are immunised.
In the UK, children should receive their first dose of the vaccine at 13 months and the second at around three years and four months.