Radiotelemetry provides an extremely powerful technology to record real-time hemodynamic measurements in experimental animals. The traditional technique for measuring blood pressure (BP) in experimental animals is the use of the tail cuff device with the advantage that it is non-invasive. However, the accuracy of this technique in measuring BP is greatly affected by a number of environmental and physiological factors. Moreover, the tail cuff method cannot provide continuous measurements. Insertion of a radiotelemetry device circumvents problems associated with the tail cuff approach. We use a DSI (Data Sciences International) radiotelemetry system that provides accurate and reliable real-time measurements of heart rate and systolic, diastolic and mean arterial BPs. Continuous or semicontinuous recording can be made in stress-free, freely moving mice for periods up to 6 weeks and across stages of the reproductive cycle including gestation, parturition and lactation. The frequent sampling of highly accurate data decreases intra- and inter-individual variability allowing conclusions to be made using considerably smaller sample sizes compared with other BP measuring techniques. In this presentation, I will describe the surgical process of inserting the radiotelemetry device including modifications to the published technique, how it can be applied to experimental designs and the challenges associated with the use of such a delicate technology.