| PRO | Boeing Procedure 
| Others |
| PRO | DOS graphics PROfile file
| Others |
| PRO | Ford Probe
| Others |
| PRO | In Favor Of
| Others |
| PRO | Paddock Radical Options
| Others |
| PRO | Patient Reported Outcome
| Others |
| PRO | Patient Reported Outcomes
| Others |
| PRO | Patient-Reported Outcome
| Others |
| PRO | Peer Review Organisation
| Others |
| PRO | Peer Review Organization
| Others |
| PRO | Peer Review Organizations
| Others |
| PRO | Peer-Review Organization
| Others |
| PRO | Peking Ragnarok Online
| Others |
| PRO | People Relating to Others
| Others |
| PRO | People, Resources, and Organizations
| Others |
| PRO | Perfectly Respectful Obedience
| Others |
| PRO | Performance Reliability Opportunity
| Others |
| PRO | Performance Reward Options
| Others |
| PRO | Performance Rights Organization
| Others |
| PRO | Personnel Recovery Officer
| Others |
| PRO | Personnel Relations Officer
| Others |
| PRO | Philippine Ragnarok Online
| Others |
| PRO | Phillipines Ragnarok Online
| Others |
| PRO | Photographic Research Organization
| Others |
| PRO | Physician Review Organization
| Others |
| PRO | Pittsburgh Relies On
| Others |
| PRO | Pittsburgh Roleplaying Organization
| Others |
| PRO | Player Referee Organization
| Others |
| PRO | Player Run Organization
| Others |
| PRO | Portable Remote Object
| Others |
| PRO | Positive Recreation Opportunities
| Others |
| PRO | Practical Regional Opportunity
| Others |
| PRO | Pray Review Organize
| Others |
| PRO | Precision Residue Opener
| Others |
| PRO | Predicament, Response, and Outcome
| Others |
| PRO | Predictable Research Online
| Others |
| PRO | Pride, Respect, and Opportunity
| Others |
| PRO | Priority Repair Order
| Others |
| PRO | Privilege, Responsibility, and Opportunity
| Others |
| PRO | Probing Rectal Orifices
| Others |
| PRO | Procedure
| Others |
| PRO | PROceed
| Others |
| PRO | Professional
| Others |
| PRO | PROfessional (for licensed professionals only)
| Others |
| PRO | Professional Racers Organization
| Others |
| PRO | Professional Recreation Organization
| Others |
| PRO | Professional Referee Organization
| Others |
| PRO | Professional Rental Owner
| Others |
| PRO | Professional Restylers Organization
| Others |
| PRO | Professional Review Organisation
| Others |
| PRO | Professional Rugby Organization
| Others |
| PRO | Profile Configuration Data
| Others |
| PRO | proflavin
| Others |
| PRO | Progressive Re-integration Opportunity
| Others |
| PRO | Progressive Rotating Order
| Others |
| PRO | Prolog File
| Others |
| PRO | prolyl
| Others |
| PRO | Pronation
| Others |
| PRO | Proper Ram-air Orientation
| Others |
| PRO | Prophylactic
| Others |
| PRO | Propulsion
| Others |
| PRO | Protections of Rights of Others
| Others |
| PRO | PROtein
| Others |
| PRO | Provencal, Old (to 1500)
| Others |
| Pro | Proverbs
| Others |
| PRO | Public Record Office
| Others |
| PRO | Public Record Office (UK Government)
| Others |
| PRO | Public Records Office
| Others |
| PRO | Public Relations Office
| Others |
| PRO | Public Relations Officer
| Others |
| PRO | Public Research Organization
| Others |
| PRO | Pumpability Reference Oil
| Others |
| PRO | Punk Rock Orchestra
| Others |
| PRO- | Previously Reported Obstructions
| Others |