Sick babies will have more intensive care beds in Melbourne, the state government has promised.

Five new neonatal intensive care unit cots will be funded in the May 6 state budget, taking the state's capacity to 100 baby beds.

Health Minister David Davis said $4 million of capital funding would get the cots ready, with a further $5.6 million a year to staff them.

''As well as newborns, this specialist equipment supports babies after surgery, infants requiring long-term ventilation and those suffering from seasonal illnesses such as bronchitis,'' Mr Davis said on Sunday.

He said the beds were most often used for babies who were born early and had complications from birth.

The beds will be installed at the Royal Children's Hospital, Monash Medical Centre, the Royal Women's Hospital and Mercy Hospital for Women.

Opposition health spokesman Gavin Jennings said the government was playing catch-up because it had failed to keep up with demand for intensive care treatment for babies.