The room opened 12 years ago and has been newly furnished to include a display of memorabilia.
Prof Lawrence, who died in 2011, was professor of obstetrics and gynaecology at Otago Medical School from 1951 to 1980.
Prof Crampton said Prof Lawrence made a "huge contribution'', notably for his interest in monitoring birthing outcomes, a practice which has become a central feature of medical research, but was less common in Prof Lawrence's time.
Prof Lawrence was also noted for the co-operative way in which he worked with obstetrician GPs.
Dunedin lawyer Bill Wright also spoke at the event, reflecting on his memories of his father.