- Kabuki syndrome 759.89
- Kahler (-Bozzolo) disease (multiple myeloma) (M9730/3) 203.0
- Kakergasia 300.9
- Kakke 265.0
- Kala-azar (Indian) (infantile) (Mediterranean) (Sudanese) 085.0
- Kalischer's syndrome (encephalocutaneous angiomatosis) 759.6
- Kallmann's syndrome (hypogonadotropic hypogonadism with anosmia) 253.4
- Kanner's syndrome (autism) (see also Psychosis, childhood) 299.0
- Kaolinosis 502
- Kaposi's
- Kartagener's syndrome or triad (sinusitis, bronchiectasis, situs inversus) 759.3
- Kasabach-Merritt syndrome (capillary hemangioma associated with thrombocytopenic purpura) 287.39
- Kaschin-Beck disease (endemic polyarthritis) - see Disease, Kaschin-Beck
- Kast's syndrome (dyschondroplasia with hemangiomas) 756.4
- Katatonia- see Catatonia
- Katayama disease or fever 120.2
- Kathisophobia 781.0
- Kawasaki disease 446.1
- Kayser-Fleischer ring (cornea) (pseudosclerosis) 275.1 [371.14]
- Kaznelson's syndrome (congenital hypoplastic anemia) 284.01
- Kearns-Sayre syndrome 277.87
- Kedani fever 081.2