  We have made a detailed spectral analysis of eleven Wide Angle Search for
Planets (WASP) planet host stars using high signal-to-noise (S/N) HARPS
spectra. Our line list was carefully selected from the spectra of the Sun and
Procyon, and we made a critical evaluation of the atomic data. The spectral
lines were measured using equivalent widths. The procedures were tested on the
Sun and Procyon prior to be being used on the WASP stars. The effective
temperature, surface gravity, microturbulent velocity and metallicity were
determined for all the stars. We show that abundances derived from high S/N
spectra are likely to be higher than those obtained from low S/N spectra, as
noise can cause the equivalent width to be underestimated. We also show that
there is a limit to the accuracy of stellar parameters that can be achieved,
despite using high S/N spectra, and the average uncertainty in effective
temperature, surface gravity, microturbulent velocity and metallicity is 83 K,
0.11 dex, 0.11 km/s and 0.10 dex respectively.
