The reunion attracted 26 old boys aged between 83 and 90 with memories of formative experiences, classmates, teachers and the cane.
Peter Fleischl credits his career success to his time at Otago Boys.
Dr Fleischl came to the school aged 13 as a refugee from Nazi-occupied Austria to escape the concentration camps.
"I arrived in New Zealand and I spoke very little English - only what I had learnt on the ship."
Despite the language difficulties in the early days of his education at Otago Boys High School, he skipped a year after two years and went straight to the upper sixth form.
He finished school as proxime accessit and went on to study medicine. He became a specialist in internal medicine in Hawkes Bay and spent several years working in refugee camps in Southeast Asia and Russia during his 60-year career.
"I had wonderful teachers [at OBHS]. The whole education system here is so free.
"It was terrible at school in Austria because of the Hitler indoctrination and anti-semitism."
The old boys were treated to a short concert by the school's choir and a tour of the school by rector Clive Rennie before celebrating with an afternoon tea.
The reunion will continue today with photographs to be taken.
