China 
Africa 
- Periodontal ligament
- Periodontium
- Perioperative
- Periosteal reaction
- Periosteum
- Peripheral
- Peripheral artery disease
- Peripheral blood lymphocytes
- Peripheral chemoreceptors
- Peripheral edema
- Peripheral nervous system
- Peripheral vision
- Periphyton
- Periplasmic
- Periprosthetic
- Perirhinal cortex
- Periscopes
- Peristalsis
- Peristaltic pump
- Peritoneal
- Peritoneal carcinomatosis
- Peritoneal cavity
- Peritoneal dialysis
- Peritonitis
- Perivascular
- Perkins Brailler
- Perl
- Perlecan
- Perlite
- Permaculture
- Permafrost
- Permalloy
- Permanent
- Permanent cell
- Permanent magnet motors
- Permanent mold casting
- Permanent press
- Permanent wilting point
- Permanganate
- Permeability
- Permeable paving
- Permeable reactive barrier
- Permeameter
- Permease
- Permeation
- Permendur
- Permethrin
- Permissible stress design
- Permit-to-work
- Permittivity
- Permutation group
- Permutation matrix
- Permutation patterns
- Permutation representation
- Permutation test
- Permutations
- Pernicious anemia
- Perovskite
- Perovskite solar cells
- Peroxidase
- Peroxide
- Peroxide value
- Peroxiredoxin
- Peroxisome proliferator-activated receptor alpha
- Peroxisome proliferator-activated receptor gamma
- Peroxisomes
- Peroxodisulfate
- Peroxydisulfate
- Peroxynitrite
- Perpendicular
- Perpendicular distance
- Perplexity
- Perrhenate
- Perseverance
- Persistence
- Persistence length
- Persistence of vision
- Persistent current
- Persistent data
- Persistent homology
- Persistent luminescence
- Persistent organic pollutants
- Persistent slip bands
- Personal care
- Personal care products
- Personal computers
- Personal data
- Personal health record
- Personal robots
- Personal watercraft
- Personal web page
- Personalized medicine
- Personalized search
- Personas
- Personnel selection
- Perspective
- Perspective-n-point
- Perspiration
- Perstraction
- Persuasive technology
- Persulfate
- Pertechnetate
- Perthite
- Perturbation
- Perturbation function
- Perturbation theory
- Perturbations
- Pertussis toxin
- Pertussis vaccine
- Pervanadyl
- Pervaporation
- Pervasive developmental disorder
- Perveance
- Pervious concrete
- Pes cavus
- Pessaries
- Pest analysis
- Pesticide application
- Pesticide drift
- Pesticide poisoning
- Pesticide residue
- Pesticides
- Petalite
- Petersen graph
- Petri dishes
- Petri nets
- Petrochemicals
- Petrographic microscope
- Petrography
- Petrol engine
- Petroleum
- Petroleum coke
- Petroleum engineering
- Petroleum ether
- Petroleum industry
- Petroleum naphtha
- Petroleum products
- Petroleum reservoir
- Petroleum traps
- Petrology
- Petrophysics
- Petroselinic acid
- Petzite
- Pewter
- Peyronie's disease
- Pfaffian
- Pfam
- Phablet
- Phage display
- Phage therapy