In the worst case, an average of six per cent of patients transferred to Monash Medical Centre waited more than two hours for admission, while in September, patients waited 51 minutes on average to be moved inside.
Patients transported to one of 24 major hospitals across the state between July and December last year waited outside for an average of 27 minutes to be transferred from an ambulance stretcher to a bed.
Other offenders included Royal Melbourne Hospital, Dandenong Hospital and Frankston Hospital, where ambulance "ramping" times exceeded an average of more than 40 minutes in at least two of the months in the data period.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Health Minister David Davis said inadequate bed numbers in key public hospitals were a key cause of the long wait times.
The Ambulance Victoria transfer data, released by the government on Thursday, would assist with the allocation of more hospital beds and understanding how hospital and ambulance services were performing.
Internal hospital processes and a collaborative approach between ambulances and hospitals also need improvement, Mr Davis said.
"Ramping of ambulances is not only not in the interests of patients, it also takes precious ambulance resources off the road," Mr Davis said.
But he said the most serious patients were being taken directly into emergency departments.
"I don't doubt that that is what occurs," Mr Davis said.
"But it's clearly not acceptable when people are waiting 50 minutes, and an hour and longer in some cases, in the back of an ambulance."
The coalition has promised to deliver 800 additional hospital beds in its first term of government.
