Opposition health spokesman Jeremy Rockliff and Opposition Leader Will Hodgman said the party would invest an initial $4.4 million as part of a long-term plan to introduce child and youth health nurses across all government schools.

Mr Rockliff said a Liberal government would appoint 20 nurses in primary and secondary schools within its first term, with each nurse looking after two schools.

He said the plan would replicate a successful trial at Wynyard High School, where a nurse helped students address mental and sexual health issues, family relationships and friendship problems.

"It's about dealing with the very serious health issues that have lifelong consequences - obesity, anxiety, depression, mental health issues," Mr Rockliff said.

Youth Network of Tasmania chief executive Joanna Siejka said the organisation had been pushing for about two years to see the Wynyard program extended to all lower socio- economic schools, after it was rated highly by students and teachers.

Ms Siejka said an evaluation of the program showed its use of mandatory meetings and mix of scheduled and informal visits had reduced the stigma associated with nurse visits.

Australian Nursing and Midwifery Federation state secretary Neroli Ellis welcomed the announcement, saying it would help children and families who slipped through the cracks.

But Health Minister Michelle O'Byrne questioned how the Liberals would fund the program, saying it would cost more than $17.6 million a year once it was fully implemented in all 196 state schools.

"When are they going to roll out nurses to all schools? How are they going to pay for it and will it be at the expense of the Child Health and Parenting Service?" she said.

Ms O'Byrne said Labor was committed to child health and healthy schools, having recently improved the Child Health and Parenting Service model of care.

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