St John organised the flash mob to raise awareness of CPR (cardiopulmonary resuscitation).
About 20 St John first-aid tutors gathered around manikins and demonstrated CPR techniques before involving members of the public.
St John national PTE (private training establishment) and NZQA manager Shirley Kerr, of Dunedin, said the event was the first of its kind and hugely successful.
''We had excellent feedback from people, who were quite amazed at just how easy it was to do CPR, and how much it had changed over the years. It was incredibly successful in raising awareness of the importance of knowing first aid.''
Christmas was a stressful time of year for some, and inevitably there were instances of people collapsing, Mrs Kerr said.
St John wanted to remind members of the public CPR was easy and anyone could do it, she said.
''It gives patients a much higher chance of survival. Anyone can do it at any time - they just have to remember '30 to two no matter who' - 30 compressions to every two breaths whether on an adult, child or baby.''
