The coordination chemistry of bis(amido)cyclodiphosph(III)azanes as dinegative chelating N-donor ligands for main-group elements is reviewed. The subject is introduced by way of an overview of convenient syntheses for bis(amino)cyclodiphosph(III)azanes and a discussion of their structures, followed by classifications of the ligands and their compounds by structure type. Detailed descriptions of syntheses and structures of bicyclic and tricyclic main-group bis(amido)cyclodiphosph(III)azane compounds, organized by groups, constitute the main part of the discussion. A summary of structural trends and potential applications concludes the review.