Our objective was to develop and validate a fully implantable telemetry device to measure renal arterial blood flow in laboratory animals under physiologically appropriate conditions. Novel flow sensors were developed and tested acutely in vivo in a stepwise fashion with external electronics to validate the sensor design and to collect data to facilitate the design of the fully implantable blood flow electronics. Infusion of dopamine (3 μg/kg/min) increased renal blood flow by 14.3 +/−2.8% in dogs implanted with the prototype novel flow sensors. Two additional female beagles were instrumented with the fully implantable device and monitored weekly for 12 weeks. A flow sensor was placed around the left renal artery and a solid state blood pressure transducer was placed in the abdominal aorta. Electronic components consisting of the signal processing circuits, telemetry transmitter and battery were implanted in the peritoneal cavity. Stable recordings of renal arterial blood flow values of ~10 ml/min/kg were obtained for both dogs. This device enables evaluation of renal arterial blood flow, blood pressure, ECG, and core temperature following pharmacologic intervention while eliminating physiologic stress associated with animal restraint.