A new reflectance spectrum of the Martian north polar cap is analyzed, and it shows water ice absorption features. This evidence confirms the results of the Viking IRTM and MAWD experiments, which indicate that the north residual polar cap of Mars is composed of water ice during the season observed (northern hemisphere spring, Ls = 50¿). The spectra presented here show that other materials are probably present as well. These other materials may be hydrated minerals, as indicated by weak absorptions in the spectrum at 1.9,2.3, and possibly 1.4 μm, but the materials seem to be otherwise spectrally bland.