- Stammering 307.0
- Standstill
- Stannosis 503
- Stanton's disease (melioidosis) 025
- Staphylitis (acute) (catarrhal) (chronic) (gangrenous) (membranous) (suppurative) (ulcerative) 528.3
- Staphylococcemia 038.10
- Staphylococcus, staphylococcal - see condition
- Staphyloderma (skin) 686.00
- Staphyloma 379.11
- Starch eating 307.52
- Stargardt's disease 362.75
- Starvation (inanition) (due to lack of food) 994.2
- Stasis
- State
- Status (post)
- Stave fracture - see Fracture, metacarpus, metacarpal bone(s)
- Steal
- Stealing, solitary, child problem (see also Disturbance, conduct) 312.1
- Steam burn - see Burn, by site
- Steatocystoma multiplex 706.2
- Steatoma (infected) 706.2
- Steatorrhea (chronic) 579.8