NO3 vertical profiles have been retrieved over the Antarctic (60¿--90¿S) from the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) lunar occultation spectra, using the visible spectral band (610--680 nm) containing NO3 absorption bands at 623 and 662 nm. The retrieved NO3 profiles agree well with calculations from a photochemical model constrained by retrieved O3 and analyzed temperatures in the altitude range between 24 and 45 km. Below about 35--40 km, observed NO3 is well reproduced by photochemical steady state calculations. Differences between observed and modeled NO3 are within the estimated accuracy of 20--35%, demonstrating the consistency of the NO3 retrieval and model.