The theoretical considerations influencing the design of scintillation dosemeters are discussed. Details are given of simple and robust probe-type scintillation dosemeters suitable for clinical application. These instruments permit the measurement of dosage-rates due to X or γ radiation of 0·5 per hour and upwards, with a probe having an outside diameter no greater than ¼ in. Experimental data are presented concerning the sensitivity, stability, energy-dependence, temperature-dependence and directional properties of dosemeters of this type incorporating various crystalline luminophors.