Abstract. The regular monitoring of the relative position of a sequence of radioactive bullets shot through the well of a vertical borehole can provide in-situ measurements of deep rock compaction. Developed in the '70s, this technology has experienced a growing interest in the '90s, but in recent years, its use and relevance in land subsidence management above producing hydrocarbon reservoirs have been often debated. The present communication analyses the state of the art of the radioactive marker technique and provides a critical review on the role that these measurements might play in the future evolution of land subsidence monitoring and modelling.