The UK stands out in the clinical, pre-clinical and health table - the only subject ranking headed by a non-American institution.
Overall, the UK takes four of the top 10 places and seven of the top 50.
Oxford is well known for its global health programme, which includes a worldwide network of research units based in Thailand, Laos, Vietnam and Kenya, funded by the Wellcome Trust.
In August last year, the university's contribution to healthcare research was recognised by an award of £95 million from the UK's National Institute for Health Research - a massive increase on initial funding of £57 million - to support "translational research", which is aimed at translating research discoveries into patient treatments.
In the clinical, pre-clinical and health table, the University of Cambridge closed the gap on its ancient rival, rising from fourth to third.
There was mixed news for other members of the "Golden Triangle": Imperial College London slipped from third to fifth, but University College London rose from seventh to sixth.
Overall, 12 countries are represented in the table.
The US dominates with 24 representatives - led by Harvard in second place and Johns Hopkins University in fourth.
Australia has five representatives in the top 50, with the University of Melbourne (joint 16th place) being the top-ranked institution outside the UK or North America.
Asia is represented by Hong Kong, Japan and Singapore, with Japan's University of Tokyo (joint 32nd place) its highest-ranked university.
South Africa makes a rare appearance in a subject ranking, with the University of Cape Town propping up the table in joint 50th position.