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The mass of the degenerate primary in A0620-00 is inferred from its spectroscopic mass function to be > 3.2 making it an excellent candidate for a black hole. The exact value of the mass depends on the orbital inclination. The inclination of a binary system can be determined from the shape of its Stokes parameter light curves if the linear polarization of the system varies as a function of orbital phase. We observed A0620-00 over one 8-hour binary period with the 4.5-m equivalent MMT. Its polarization in the visible (5000 A-9000 A) is variable with orbital phase. Using the standard theory of Brown, McLean, and Emslie (1978), we derive an orbital inclination of i = 57° (+20°, -50°), where the error is the 90% confidence interval derived by the method of Simmons, . The large uncertainty in the derived value of the inclination is directly related to the statistical precision of the observations, which is in turn limited by the relative faintness of the source, i = 57° corresponds to a mass of the compact primary of 6.6 but the large uncertainty in our measured value of the inclination allows the derived mass of A0620-00 to be as low as 3.8 SJ£ 0 . If 5 337 0 * s taken to be the maximum mass of any degenerate configuration consistent with general relativity except a black hole, then the mass of A0620-00 is still not well-enough determined to conclude that it must be a black hole.