The behavior of the sensitized fluorescent spectrum of sodium, produced by irradiating Hg–Na–N2 mixtures with Hg 2537 Å resonance radiation, was studied in relation to N2 pressure. In this ternary vapor-gas system, the sodium atoms become excited by collisional transfer from Hg 63P1 atoms and also from Hg 63P0 atoms which are formed in Hg(63P1) + N2 collisions. The spontaneous decay of the collisionally populated S, P, and D sodium states gives rise to the fluorescent spectrum and their radiationless decay (quenching) caused by collisions with N2 molecules, manifests itself in a decrease of the fluorescent intensities as N2 pressure is increased. An analysis of the variation of the fluorescent intensities with N2 pressure, yielded 15 quenching cross sections for various S, P, and D sodium states, which appear to exhibit resonance properties with respect to upward vibrational transitions in N2.