Near-infrared spectroscopy (NIRS) is a non-invasive optical technique increasingly used to assess muscle oxygenation during exercise, although the possible interference by cutaneous circulation remains a major limitation of the technique (Davis et al. 2006). Spatially resolved spectroscopy (SRS) was proven to effectively reduce the influence of extracranial blood flow in cerebrovascular assessesments as compared to original Beer-Lambert (BL) NIRS but its potential effectiveness in muscle circulation is currently unexplored. The aim of this study is to compare BL vs SRS indices of blood volume during selective cutaneous and muscle hyperemia. To this purpose we performed the NIRS assessment with the NIRO 500 (Hamamatsu) which provides simultaneous BL and SRS indices of blood volume, tHb and THI, respectively. In 10 healthy subjects enrolled in the study NIRS optodes were placed along the belly of the flexor carpi radialis (left arm) and skin blood flow was measured with laser-Doppler flowmetry. Selective cutaneous vasodilatation was obtained by locally warming the left forearm with warm air flow and selective muscle dilatation was obtained by a 10-s lasting maximum voluntary wrist flexion, producing an exercise-hyperemia in the relevant muscles In the two conditions changes in blood volume were computed as absolute changes for tHb (in uM*cm) and relative changes (%) for THI. In addition a warm/exercise ratio (WER) was computed as the ratio between changes observed during the warm- and exercise-hyperaemia (in %) This index quantifies and allows to compare the dependence on cutaneous circulation of THI and tHb: the higher the WER, the higher the dependence. Warming (26.6± 0.9 to 33.2±1.3 °C) produced marked changes in cHB in all subjects (19.5±7.4 uM*cm) associated with the increase in skin blood flow while THI was unresponsive to warming in 5 out of 9 subjects and highly responsive in the others (average on all subjects11.8±18.6 %) Consequently, also the warm/exercise ratio exhibited a bimodal distribution for THI: 2.2 ±22.5% (indicating that the response to warming is 2% of exercise hyperemia) in 5 subjects and 531±261 % (n=4). WER for tHb was on average: 333±258 %. The results confirm that changes in skin blood flow can markedly affect NIRS parameters. As observed for cerebrovascular monitoring (Canova et al. 2011) SRS spectroscopy appears to be less dependent on cutaneous circulation than the classical BL technique. The reason for high WER values in the THI of 4 subject may represent an additional problem for NIRS assesments whose excact nature remains to be ascertained.