BACKGROUND: A Stellate ganglion block (SGB) is a sympathetic nerve block method which has been used most frequently in pain clinics due to its wide range of indications. However, SGB leads to regional sympathetic denervation of the heart and to changes in the hemodynamics. The aim of this study was to compare hemodynamic effects as well as echocardiographic changes after a left SGB (LSGB). METHODS: Fourteen healthy male volunteers were studied. The LSGB was performed with 1% mepicacaine 6 ml. Arterial blood pressure, electrocardiographic and echocardiographic variables were measured before the LSGB, 15 and 30 minutes after the LSGB. RESULTS: Arterial blood pressure, ejection fraction and transmitral inflow velocity variables showed no significant changes compared to pre-LSGB values. P-P interval increased significantly 15 minutes after the LSGB, and the Q-T interval increased significantly 30 minutes after the LSGB. The diastolic pulmonary venous flow velocity decreased significantly 15 minutes after the LSGB. CONCLUSIONS: These results showed that a LSGB decreased the heart rate without detrimental changes of left ventricular relaxation in healthy male volunteers.