Hyperfine polarization quantum beats caused by the reversible interchange of molecular polarization and nuclear spin polarization are observed in the fluorescence of C2N2, following laser absorption on the 4(0)(1) ($) over tilde A((1) Sigma(u)(-)) <-- ($) over tilde X((1) Sigma(g)(+)) band at 219 nm. Cross sections for collisional quenching and alignment depolarization of the fluorescence, determined by quantum beat spectroscopy, are 88 and 285 Angstrom(2), respectively.