  Previous investigations on hydrogen-rich white dwarfs generally yield only
very small rotational velocities (v_rot sin i). We have analyzed line profiles
in high-resolution optical spectra of eight hydrogen-deficient (pre-) white
dwarfs and find deviations from the dominant Stark line broadening in five
cases which, interpreted as an effect of stellar rotation, indicate projected
rotational velocities of 40 - 70 km/sec. For the three least luminous stars
upper limits of v_rot sin i = 15 - 25 km/sec could be derived only. The
resulting velocities correlate with luminosity and mass. However, since the
mass-loss rate is correlated to the luminosity of a star, the observed line
profiles may be affected by a stellar wind as well. In the case of RX
J2117.1+3412, this would solve discrepancies to results of pulsational modeling
(v_rot sin i ~ 0).
