  In this letter recent results on the nodal precession of accretion discs in
close binaries are applied to the discs in some X-ray binary systems. The ratio
between the tidally forced precession period and the binary orbital period is
given, as well as the condition required for the rigid precession of gaseous
Keplerian discs. Hence the minimum precessional period that may be supported by
a fluid Keplerian disc is determined. It is concluded that near rigid body
precession of tilted accretion discs can occur and generally reproduce
observationally inferred precession periods, for reasonable system parameters.
In particular long periods in SS433, Her X-1, LMC X-4 and SMC X-1 can be fit by
the tidal model. It is also found that the precession period that has been
tentatively put forward for Cyg X-2 cannot be accomodated by a tidally
precessing disc model for any realistic choice of system parameters.
