The top 10 medical research institutions in the world, ranked according to their research output and impact, are:
1. Harvard Medical School – United States
2. Johns Hopkins University School of Medicine – United States
3. University of Oxford Medical Sciences Division – United Kingdom
4. Stanford University School of Medicine – United States
5. University of Cambridge School of Clinical Medicine – United Kingdom
6. Karolinska Institute – Sweden
7. University of California, San Francisco School of Medicine – United States
8. Washington University School of Medicine in St. Louis – United States
9. Yale School of Medicine – United States
10. University of Toronto Faculty of Medicine – Canada
Please note that rankings may vary depending on different sources and criteria used for evaluation.