This study examines the use of reflectance measurements acquired with field spectroradiometers and with the airborne Multispectral Infrared and Visible Imaging Spectrometer (MIVIS) for mapping canopy water content in a poplar plantation located in the Ticino Natural Park (Italy). Different water spectral indices were investigated by using Ordinary Least Square (OLS) regression techniques in order to determine the equivalent water thickness (EWT) and the gravimetric water content (GWC) at leaf and plantation level. Significant correlations were found between EWT and selected vegetation indices at leaf level. The results have shown that leaf reflectance is related to EWT but not to gravimetric water content. However, at canopy level, spectral indices sensing canopy water content appear to respond not only to the canopy water content but also to canopy structure, providing a useful method for mapping the vegetation leaf area index at the experimental site. © 2006 American Institute of Physics.