The problem of a centred-inclined radiating slot cut in a broad wall of a rectangular waveguide and excited by a TE10mode wave is considered. Pertinent integral equations for the slot aperture electric field are solved using the method of moments. Scattering characteristics of the slot are then analysed including resonant length and the equivalent series impedance. Numerical results on resonant length and the normalised series impedance in a universal form are obtained over a range of values of tilt, slot width, waveguide height, wall thickness and frequency. These results should find applications in the design of arrays of centred-inclined slots.