BACKGROUND. Impedance cardiography (IC) is a complementary diagnostic test used in the study of arterial hypertension (AHT) and in the optimization of antihypertensive therapy. It is easy-to-execute, non-operator-dependent and cost-effective. It analyses and registers hemodynamic changes through the measurement of electrical resistance changes in the thorax and translates them graphically as impedance and electrocardiogram waveforms. IC has evolved in recent years, making it an attractive and economical tool, particularly in screening settings and there is extensive published literature on its usefulness. More widespread use of IC has been limited due to limitations of the studies, mostly cross-sectional, with small samples, recruiting hemodynamically stable patients and providing inconsistent estimates of accuracy and reproducibility in different settings.