An automated method of measuring cranial shape is described and tested on groups of extant and fossil hominoids. The method of Fourier analysis is applied to the lateral cranial projections. The patterns and extents of discrimination produced by the sine-cosine and amplitude phase-lag spectra are compared. The sine-cosine series is utilized to determine the interrelationships of extinct and extant hominoids. It is demonstrated that the patterns of discrimination are consistent with current taxonomic classifications of the extant species. It seems that Fourier analysis can, in certain circumstances, offer advantages over more traditional methods of shape measurement, especially because of its relative independence of the need to define ‘homologous landmarks’.