Two indium-containing analogs of the mineral alluaudite, Na3In2(PO4)3and Na3In2(AsO4)3, have been synthesized hydrothermally and structurally characterized by single-crystal and powder X-ray diffraction, respectively. Crystal data: Na3In2(PO4) 3,a=12.450(1),b=12.786(1),c=6.5920(7) Å,β=114.174(2)°,V=957.38 Å3,Z=4; Na3In2(AsO4)3, as above excepta=12.6037(2),b=13.1711(2),c=6.8342(1) Å,β=113.743(1)°,V=1038.48 Å3. The two compounds are isostructural. The main structural feature is the presence of infinite chains of edge-sharing In2O10dimers and NaO6octahedra, which are linked together by PO4or AsO4tetrahedra to form a framework structure, enclosing two types of tunnels where Na+cations reside. TheX(1) site of the alluaudite structure is occupied by Na+, whereas theX(2) site is empty. Instead, a site which is shifted from theX(2) site by ±1/4 alongzis occupied by Na+.