Molecular Medicine and Pathology specialist Mark Thomas wants New Zealanders to consume fewer antibiotics.
The University of Auckland Associate Professor said half of all pharmaceutical prescriptions were "not doing any good".
Thomas said an "an increasing number" of germs were developing a resistance to antibiotics.
This has occurred with germs such as common E. coli infections, which have occasionally resisted all antibiotics.
"I would like to see less prescribing of antibiotics in the community in New Zealand for all population groups," he said.
Thomas said European and Asian New Zealanders were the ethnic groups that especially needed fewer antibiotics as they had lower rates of infectious diseases than Maori and Pasifika.
He would like to educate society about antibiotics and encourage those who write antibiotic prescriptions to do so less frequently.
"The sooner we make a difference, the sooner we can put things right."