My thesis work concerns the study of a sample of young spectroscopic binaries (SB) in Galactic star formation regions by means of echelle spectra (FEROS @ ESO 1.5m) obtained in the course of a three years campaign. I acquired and reduced some of these data. Spectra are now being analysed using the cross-correlation method for radial velocities determination. In fact, the study of binary systems, once the orbital elements have been evaluated, allows direct determination of the physical parameters of the two components which can be used to constrain PMS evolution models. We plan to extend these methods, in the near future, for the detection of extrasolar planets also using the TT1.