Medical imaging and pathology services at the Murray Bridge hospital should not be privatised, opposition health spokesman Chris Picton says.
The state MP visited Murray Bridge last week to speak with staff at the hospital's medical imaging unit and its SA Pathology lab.
The state government is considering whether both should be operated by private providers, an idea Mr Picton opposed.
"Those services are valued and they do a good job," he said.
"I'd be calling on the government not to outsource or privatise those services."
A private owner would likely consolidate pathology labs in the city, resulting in the loss of up to 20 local jobs and longer test result waiting times for patients, he speculated.
He also visited the SA Ambulance Service, who he said were spending about 15 hours per month stuck in Adelaide because of ramping, or overcrowding, at metropolitan hospitals.
The government needed to find a way of coping with demand, Mr Picton said - whenever a Murray Bridge crew was in Adelaide, it could not respond to emergencies here.