- Pelger-Huët anomaly or syndrome (hereditary hyposegmentation) 288.2
- Peliosis (rheumatica) 287.0
- Pelizaeus-Merzbacher
- Pellagra (alcoholic or with alcoholism) 265.2
- Pellagra-cerebellar-ataxia-renal aminoaciduria syndrome 270.0
- Pellegrini (-Stieda) disease or syndrome (calcification, knee joint) 726.62
- Pellegrini's disease (calcification, knee joint) 726.62
- Pellizzi's syndrome (pineal) 259.8
- Pelvic - see also condition
- Pelvioectasis 591
- Pelviolithiasis 592.0
- Pelviperitonitis
- Pelvis, pelvic - see also condition or type
- Pemphigoid 694.5
- Pemphigus 694.4
- Pendred's syndrome (familial goiter with deaf-mutism) 243
- Pendulous
- Penetrating wound - see also Wound, open, by site
- Penetration, pregnant uterus by instrument
- Penfield's syndrome (see also Epilepsy) 345.5
- Penicilliosis of lung 117.3
- Penis - see condition