An overview of the principles, capabilities, and applications of proton magnetic resonance thermal analysis (PMRTA) is given. Its range of possible applications is described and results from some recent studies are discussed. PMRTA enables the dynamic state of materials with significant hydrogen contents to be investigated during pyrolysis. This is a thermal analysis technique which uses pulsed proton NMR ’broad line’ spectroscopy as the means of determining the behaviour of the sample under investigation. Samples are subjected to a controlled temperature programme either ramped at a fixed rate (up to 20 degrees C min(-1)) from 40 degrees C up to 600 degrees C, or held at a fixed temperature within this range. H-1 NMR measurements are made at intervals throughout the temperature programme. These in-situ measurements allow the progress of thermal transformations to be determined. The solid echo signals obtained for a rigid lattice are representative of the entire hydrogen population of the sample and the peak echo is a measure of the total hydrogen content. Deviations from this situation during pyrolysis require corrections to be made. The hydrogen content can therefore be monitored semi-quantitatively in the residual sample throughout the temperature programme. Molecular properties affect the transverse relaxation signal so that the proportion and extent bf hydrogen mobility can be determined. Thermoplastic events, material loss and interactions between materials can be detected and properties predicted using validated correlations with data from established methods of analysis. It may be applied to materials which contain a significant amount of H-2 and minimal moisture or magnetic material. The instrument was originally developed at CSIRO, Australia, for use in the investigation of coals and related materials. Correlations of PMRTA parameters with a range of coal properties were established with a suite of Australian coals. At CRE the correlations of PMRTA parameters with coal properties have been developed further with a suite of UK and international coals. Recent studies have included investigation of a range of coal behaviours including the non-additive swelling of some coal blends (an important property for coals fired on grate stokers), coal spitting (of importance for coals burned in top feed stokers and domestic coals), effects of microwaving on coal properties (a technique being investigated with a view to reducing coal sulphur contents), coal spontaneous heating (a coal behaviour which it is not currently possible to predict because of the large number of factors involved), coking properties (coal plasticity and fluidity are crucial properties for successful coke production and PMRTA is a useful tool for investigating these properties) and behaviours of coal maceral concentrates. These are described and potential future applications for the technique, suggested.