Vitreous AgPO 3 is of technological interest as a host for solid-state electrolytes, whereas its crystalline counterpart is a good model system for structural and transport modelling. In this paper we present 3 1 P NMR-MAS evidence of two crystallographically non-equivalent phosphorous atoms in AgPO 3 crystal. Both glass and crystal are made of long chains of PO 4 tetrahedra connected by corners. The glass structure is characterized by a wide distribution of bond lengths and angles.