The sign and approximate magnitude of the gyromagnetic ratio for the nu(5) doubly degenerate bending mode of acetylene are determined by use of rotationally resolved magnetic dichroism measurement of transitions to the singly excited vibrational state. By analysis of the J-dependence of the apparent g-value for this transition, the vibrational g-factor was determined from the experimental spectrum by moment analysis to be g(nu) = 0.48(25). This is the first such determination of g(nu) in a degenerate state of a linear molecule using MVCD and the first determination of g(nu) for the nu(5) mode in acetylene. Simulated MVCD spectra based on the accepted ground state rotational g-value and this determination of g(nu) agree with the observed intensity pattern, confirming the analysis.