RS Vul (HD 180939, VMax =7.0, B5V+G1III) is a semi-detached eclipsing binary with a period of 4.4776635 days. High signal-to-noise (S/N ≃ 100) spectra have been obtained with the 1.2m telescope and coudé Reticon spectrograph of the Dominion Astrophysical Observatory. The FeI 4045Å, 4227Å (blend of CaI, FeI and TiII) lines and G-band (4300Å) of the secondary are weakly visible on the spectra. Radial velocities measured from the spectra using a digital cross-correlation technique (Hill, 1982) have been used to compute a new spectroscopic orbit for the system. The primary and secondary semi-amplitudes are 54.0 ± 1.0 kms−1 and 204 ± 2 kms−1 respectively, assuming a circular orbit. The primary and secondary orbits are “decoupled” in the sense that velocities for the components can be measured separately on the same spectrum by using B5V and GOV template spectra. The secondary semi-amplitude is 17% larger than that found by Popper (1982), but the mass ratio (3.7) is identical to that found by Hutchings and Hill (1971).