The title compound, C26H55N11P4, consists of a bicyclic phosphazene ring with five bulky pyrrolidino and one propylamino group, together with a second propylamino group bridging the two P atoms. The asymmetric unit contains two molecules with very similar conformations. The bulky substituents are instrumental in determining the bicyclic P4N5 ring conformation. Each of the fused six-membered N3P3 rings is in a sofa conformation. The P-N distances in the bridge are non-equivalent and one of them is the longest P-N bond in the molecule. The hybridization of the bridging N atom is pyramidal. The single and double P-N bonds cannot easily be distinguished, since they retain their phosphazenic character in the phosphazene macro-rings.