An average of $17,500 each day has been posted or banked directly since envelopes were sent to Otago and Southland residents at the start of the month.
Envelopes containing amounts ranging from a handful of coins to large bank donations have been gratefully received by those behind the campaign.
The campaign, which was launched on January 20, aims to raise $3 million to fund a chair in neurosurgery to lead a research unit centre of excellence in neurosurgery.
The person filling the Neurological Foundation chair in neurosurgery will spend half their time as a neurosurgeon at Dunedin Hospital serving Otago and Southland residents, and the other half on research and teaching.
University of Otago pro vice-chancellor health sciences Peter Crampton said he was excited by the campaign's early success.
"This is testament to the importance of the neurosurgical service to the people of Southland, Otago and the South Island. We now need to focus on keeping up the momentum."
Neurological Foundation executive director Max Ritchie said to reach the halfway point after only a month was "remarkable and an indication of the wonderful support we have received from the Otago and Southland communities and elsewhere".
