This dataset  contains both experimental and numerical data relating to figures presented in the paper, "Circular dichroism in higher-order diffraction beams from chiral quasi-planar nanostructures". The experimental data contain measurements obtained from atomic force microscopy (AFM) and the spectra used to plot far-field circular dichroism (CD) diffraction patterns. The numerical data contain simulated spectra used to plot a corresponding set of far-field CD diffraction patterns, and electric near-field data corresponding to maximum and minimum CD responses in the far-field.