The Precision Solar SpectroRadiometer (PSR) is a new spectroradiometer developed at Physikalisch-Meteorologisches Observatorium Davos-World Radiation Center (PMOD-WRC), Davos, measuring Direct Solar Irradiance at the surface, in the 300–1020 nm spectral range at high temporal resolution. The purpose of this work is to investigate the instrument's potential of retrieving Integrated Water Vapor (IWV) using its spectral measurements. Two different approaches were developed in order to retrieve IWV, the first one using single channel/wavelength measurements, following a theoretical water vapor high absorption wavelength, and the second one using direct sun irradiance integrated at a certain spectral region. IWV results have been validated using a 2-year dataset, consisting of an AERONET sun- photometer Cimel CE318, a Global Positioning System (GPS), a Microwave Radiometer Profiler (MWP) and radiosonde retrievals recorded at Meteorological Observatorium Lindenberg, Germany. For the monochromatic approach, better agreement with retrievals from other methods/instruments was achieved using the 946 nm channel, while for the spectral approach using the 934–948 nm window. Compared to other instruments' retrievals, the monochromatic approach leads to mean relative differences up to 3.3 % with the coefficient of determination (R<sup>2</sup>) being in the region of 0.87–0.95, while for the spectral approach mean relative differences up to 0.7 % were recorded with R<sup>2</sup> in the region of 0.96–0.98. Uncertainties related to IWV retrieval methods were investigated and found to be less than 0.28 cm for both methods. Absolute IWV deviations of differences between PSR and other instruments were determined the range of 0.08–0.30 cm and only in extreme cases would reach up to 15 %.