  We present a detailed analysis of S-wave Kpi scattering up to 2 GeV, making
use of the resonance chiral Lagrangian predictions together with a suitable
unitarisation method. Our approach incorporates known theoretical constraints
at low and high energies. The present experimental status, with partly
conflicting data from different experiments, is discussed. Our analysis allows
to resolve some experimental ambiguities, but better data are needed in order
to determine the cross-section in the higher-energy range. Our best fits are
used to determine the masses and widths of the relevant scalar resonances in
this energy region.
