Background/Aims: Laser Doppler flowmetry ( LDF) was used to determine the influence of acute myocardial infarction (AMI) and of successful reperfusion treatment on basal skin blood flow and its oscillatory components. Methods: Skin LDF was performed on all extremities in 58 patients 4 - 9 days after AMI (Killip class I), and in 71 healthy age- and sex-matched controls. Wavelet analysis was applied to evaluate oscillatory components within the interval 0.005-2 Hz. Results: AMI patients had reduced mean flow (p < 0.01) and oscillatory components (p < 0.04) in all extremities. Reperfused (n = 40), compared to nonreperfused ( n = 18), patients had higher mean flow and total spectral amplitude at all recording points. The difference was statistically significant only in legs ( group median LDF in the left leg was 9.68 AU for reperfused and 5.71 AU for nonreperfused patients, p < 0.04, and 11.47 and 4.24 AU in the right leg, p < 0.01). Reperfused patients had significantly higher total spectral amplitude in both legs (p < 0.04). Conclusions: In AMI patients, reduced skin blood flow and its oscillatory components may reflect ongoing neurohumoral activation despite absence of clinically apparent heart failure. The reduction of blood flow and its oscillatory components was larger in nonreperfused AMI patients, although they had a comparable left ventricular function.