| Abbreviations | Meaning |
 | PMAC | Pharmaceutical Manufacturers Association Of Canada; Phenylmercuric Acetate; Programmable Multi-axis Controller |
 | PMHAB | Provincial Mental Health Advisory Board [Canada] |
 | PNHA | Physicians National Housestaff Association |
 | POS | Piedmont Orthopaedic Society |
 | POSI | Paediatric Orthopaedic Society Of India |
 | POSNA | Pediatric Orthopaedic Society Of North America (AAOS Specialty Societies) |
 | PPS | Physician, Patient And Society |
 | PPS | Physician, Patient And Society [course] |
 | PRB | Basic Proline-rich Protein; Prosthetics Research Board |
 | PRRB | Provider Reimbursement Review Board |
 | PSI | Psychiatric Society For Informatics |
 | PWD | Posterior Wall In Diastole; Printed Wiring Board |
 | RACGP | Royal Australian College Of General Practitioners |
 | RACS | Royal Australasian College Of Surgeons |
 | RB | Rating Board |
 | RBNA | Royal British Nurses Association |
 | RCGP | Royal College Of General Practitioners |
 | RCM | Royal College Of Midwives |
 | RCN | Right Caudate Nucleus; Royal College Of Nursing |
 | RCOG | Royal College Of Obstetricians And Gynaecologists |
 | RCP | Royal College Of Physicians |
 | RCP | Radiochemical Purity; Red Cell Protoporphyrin; Retrocorneal Pigmentation; Riboflavin Carrier Protein; Royal College Of Physicians |
 | RCPATH | Royal College Of Pathologists |
 | RCPSC | Royal College Of Physicians And Surgeons Of Canada |
 | RCPSGLAS | Royal College Of Physicians And Surgeons, Glasgow |
 | RCS | Royal College Of Science |
 | RCS | Royal College Of Surgeons |
 | RCSE | Royal College Of Surgeons, Edinburgh |
 | RCSED | Royal College Of Surgeons Of Edinburgh |
 | RCSENG | Royal College Of Surgeons Of England |
 | RCSI | Royal College Of Surgeons In Ireland |
 | RCVS | Royal College Of Veterinary Surgeons |
 | RESNA | Rehabilitation Engineering And Assistive Technology Society Of North American |
 | RESNA | Rehabilitation Engineering Society Of North America |
 | RHB | Regional Hospital Board [UK]; Right Heart Bypass |
 | RHBS | Regional Hospital Boards |
 | RHCSA | Regional Hospitals Consultants' And Specialists' Association |
 | RJOS | Ruth Jackson Orthopaedic Society (also: AAOS Specialty Societies) |
 | RMPA | Royal Medico-Psychological Association |
 | RSH | Royal Society Of Health |
 | RSM | Royal Society Of Medicine |
 | RSM | Risk Screening Model; Royal Society Of Medicine |
 | RSNA | Radiological Society Of North America |
 | RSNA | Radiological Society Of North America; Renal Sympathetic Nerve Activity |
 | RSPCA | Royal Society For The Prevention Of Cruelty To Animals |
 | RSPH | Royal Society For The Promotion Of Health |
 | RSTMH | Royal Society Of Tropical Medicine And Hygiene |
 | SAB | Society Of American Bacteriologists |
 | SAB | Scientific Advisory Board |
 | SACNAS | Society For The Advancement Of Chicanos And Native Americans In Science |