- Laboratory Techniques in Immunology
- Laboratory Techniques in Microbiology
- Lactic Acid Bacteria
- Lactobacillus
- Lancefield, Rebecca Craighill (1895-1981)
- Landsteiner, Karl (1868-1943)
- Latent Viruses and Diseases
- Lederberg, Joshua (1925- )
- Leeuwenhoek, Antoni Van (1632-1723)
- Legionnaires' Disease
- Leprosy
- Lichen Planus
- Lichens
- Life, Origin of
- Lipopolysaccharide and Its Constituents
- Lister, Joseph (1827-1912)
- Loeffler, Friedrich August Johannes (1852-1915)
- Luminescent Bacteria
- Lyme Disease
- Lysogeny
- Lysosome
