A new empirical mass-luminosity relation for Main-Sequence. stars in the range -0.6<logm<+0.1 is derived. The sample selected for computations is a merger of visual doubles and spectroscopic binaries, all of them with minor observational errors. To these measures linear and secondorder fits were applied; their r.m.s. errors are ±0.3 in magnitude and ±0.025 in logarithm of the stellar mass. An application to the luminosity function of nearby stars is then presented.