Food industry is interested in the utilisation of legume flours for the improvement the nutritional quality of cereal based foods. In this context, this research aimed at investigating the beneficial properties of different commercial carob seed flours -Ceratonia siliqua L.-.In particular, we determined chemical parameters (protein, fat, ash, soluble and insoluble fibre) by standard AOAC methods, lignans (secoisolariciresinol, lariciresinol, isolariciresinol, pinoresinol) by HPLC methods, the Total Polyphenol Content (TPC) by the Folin Ciocalteau method and the antioxidant properties by the FRAP assay.The carob germ flour and the raw carob seed flour reached the highest insoluble fibre, lignan and total polyphenols content and these results were matched by their antioxidant properties. Different carob flours showed a different distribution of the various lignans.