Luminescence dosimeters, including thermoluminescent dosimeters (TLDs), optically stimulated luminescence dosimeters (OSLDs), and radiophotoluminescent dosimeters (RPLDs), are extensively utilized in medical dosimetry owing to their accuracy and favorable characteristics. Additionally, practical aspects such as compact dimensions, availability, reusability, and overall operational simplicity have further facilitated their widespread adoption. Alanine, an amino acid traditionally employed in high-dose dosimetry for radiation processing, has recently been shown to achieve the accuracy required for radiotherapy-level dosimetry. Both luminescence dosimeters and alanine are passive devices, in which the absorbed energy is retained within the dosimetric material with small signal degradation over time following irradiation. This characteristic, in combination with other properties, renders them particularly suitable for clinical usage, inter-institution dose comparisons, and dosimetry audits. This chapter examines the theoretical foundations of signal formation, delineates the specific characteristics of the most employed dosimeters and their related instrumentation, characterizes their physical properties, reviews typical applications, and critically evaluates the advantages and limitations of using luminescence dosimeters and alanine in medical applications.