MRI-based temperature imaging that exploits the temperature-sensitive water proton resonant frequency shift is currently the only available method for reliable quantification of temperature changes in vivo. Extensive pre-clinical work has been performed to validate this method for guiding thermal therapies. That work has shown the method to be useful for all stages of the thermal therapy, from resolving heating below the threshold for damage to ensuring that the thermal exposure is sufficient within the target volume and protecting surrounding critical structures and to accurately predicting the extent of the ablated volume. In this paper, these validation studies will be reviewed. In addition, clinical studies that have shown this method feasible in human treatments will be overviewed.