A new parameter is proposed for the characterization of the multiple scattering observed in tracks of charged particles. This parameter is the mean value of the cosine of a constant times the projected scattering angle. The theoretical relation between the mean value of the cosine parameter and the momentum-velocity productpβ of the particle can be calculated analytically in a simple way. A theoretical dispersion is also calculable, thereby giving an estimate of the error. This is in contrast to the parameter usually used in track measurements; namely, the mean absolute value of the projected scattering angle where the mean value calculation is complicated and the dispersion is excessively sensitive to the form of the scattering law at large angles. Theoretical results for the mean value and dispersion of the cosine parameter are given for two cases: 1) angles between successive tangents at intervals along the track; 2) angles between successive chords. The effect of the correlation between successive measurements is considered in the latter case.