Skin vasomotion is the rhythmic variation of skin microvessel diameter responsible for skin microcirculatory blood flow oscillation, the so called blood flowmotion. Experimental and clinical findings suggest that vasomotion depends on different mechanisms, such as the endothelial activity, the spontaneous myogenic activity of the microvascular wall and the local sympathetic activity. Since some skin LDF oscillatory components reflect skin vasomotion, we can indirectly investigate this microvascular behavior in humans by means of the spectral analysis of skin laser Doppler flowmetry (LDF) tracing. In particular, it has been demonstrated that LDF oscillations in the frequency range of 0.01-0.02 Hz, 0.02-0.06 Hz and 0.006-0.2 Hz are respectively related to the endothelial-dependent, the sympathetic-dependent and the myogenic-dependent vasomotion. The spectral amplitude of each of these LDF oscillations has been suggested to reflect the efficiency of the corresponding vasomotion mechanism. Several studies have been performed using this method in patients with different pathological conditions, such as peripheral obstructive arterial disease, arterial hypertension, chronic renal failure, hypercholesterolemia, diabetes or systemic sclerosis. When analyzed with tests such as skin post-ischemic hyperaemia or acetylcholine iontophoresis, these pathological conditions resulted to be characterized by a perturbed skin vasomotion. The results of these studies will be presented and their usefulness in understanding the pathophysiology of the investigated diseases, will be discussed.