There has been a rise in the notifications of measles, mumps and rubella over the past 18 months, latest figures have revealed.
The MMR jag has been blamed by some for a rise in childhood autism
Incidences of suspected mumps reported by doctors rose by 27%, rubella by 22% and measles by 18% in children under 15.
The statistics were released by the Information and Statistics Division of NHS Scotland.
The disclosure comes at a time when take-up rates for the controversial measles, mumps and rubella (MMR) vaccine are running at their lowest levels for at least eight years.
The three-in-one jab has been blamed by some for a rise in childhood autism.
However, there were some positive results contained within the report, with the news that notifications by doctors of meningitis have fallen.
New notifications of mumps in children under 15 rose from 98 in 2001 to 124 in 2002, according to the findings, which cover the year 2002 and the first half-year period of 2003.
Notifications of rubella increased from 222 in 2001 to 270 in 2002.
The downward trend in new notifications of measles halted in 2002 with the number of notifications going up from 301 to 356 in the same period.
Scotland's Chief Medical Officer Dr Mac Armstrong reminded parents of the importance of immunising their children.
He said: "Measles, mumps and rubella are very serious illnesses which can severely impair sight and hearing and can be fatal.
"It is vitally important that parents ensure their children are fully protected against these serious diseases.
"A rise in incidences of these diseases is worrying but it shows that GPs are on the look-out for all three.
"While only a minority of these reports are eventually determined as an actual infection, health professionals are clearly concerned that these three serious and preventable diseases are still affecting children and young adults."
He added: "Research has shown that the MMR jab is the safest means of ensuring that young children are protected against all three diseases.
Wider immunisation has helped reduce meningitis cases
"While we are by no means on the verge of an epidemic, a fall in uptake levels leaves unimmunised children and the population as a whole at risk."
Information on communicable diseases is collated by the Scottish Centre for Infection and Environmental Health, who provide advice to health boards and local authorities in Scotland.
Notifications of meningitis have fallen by almost a third from 256 in 2001 to 175 in 2002.
Dr Armstrong attributed this partly to the extension last year of the Meningitis C vaccine to all those aged under 25.
Whooping cough notifications have also dropped slightly, according to the report.
But chickenpox among children has gone up by a third in the time period covered by the study.
The current take-up rate for the MMR jab stands at 85.8%, way below the 95% "herd immunity" level deemed by experts to be the level which gives protection to the community as a whole.