Dark chocolate (DC) is rich in cocoa, a substance with anti-oxidative and antihypertensive properties. The effect of DC on renal hemodynamics is poorly understood. The aim of this randomized, placebo-controlled study was to investigate whether DC induces changes in blood pressure and renal perfusion as assessed with Doppler ultrasound – both at rest and during sympathetic stimulation – compared to cocoa-free white chocolate (WC).