Potato Yellow Vein Virus (PYVV) threatens potato production in South America. Visual field monitoring is commonly used to detect PYVV on potato crops but the disease is generally detected only after significant damage has occurred to photosynthetic tissues. Therefore, a method for detecting the disease before yields are severely affected would be useful. Remotely sensed multispectral reflectance, based on the reflectivity and propagation of light radiation inside plant tissues, was tested for the detection of PYVV infection in potato plants grown indoors. A visual assessment of disease symptoms in both virus-infected and virus-free plants was compared to monitoring based on spectroradiometry and multispectral photographic images of the same plants, recorded during their growth and development. Results showed that changes in reflectance in certain regions of the electromagnetic spectrum, indicative of disturbances in light reflection by vascular tissues in infected plants, measured with an spectroradiometer, as well as derived spectral Vegetation Indices such as NDVI, SAVI, and IPVI, provide early detection of viral infection, long before symptoms of chlorosis can be detected by the trained eye. © 2009 Taylor & Francis.