The two‐dimensional linear gravity waves created by a moving oscillatory source in an incompressible, inviscid, electrically conducting fluid of infinite depth where a constant magnetic field acts outside the air‐water interface are considered. To determine the unsteady asymptotic waves, Bleistien's method had been applied to the Fourier transform solution. Several physically interesting results about the four waves generated, together with their fronts, are found and also the effect of magnetic force on the gravity waves has been studied. Copyright © 1995 John Wiley & Sons, Ltd