The structure of the new compound Nd 16 Ti 5 S 17 O 17 was determined by single-crystal X-ray diffraction. The following data were obtained: M r =3364.4 gmol −1 , tetragonal symmetry, space group I4/m (No. 87), unit cell parameters a=22.153(2) Å, c=3.9426(3) Å, V=1935 Å 3 , Z=2. Refinement for 1282 unique reflections and 62 parameters converged to the reliability factor R=2.22% (for 1059 reflections with I≥3σ(I)). The structure can be schematically described on the basis of [NdS] plane fragments connected by “(Nd 8 S 9 )” clusters, which delimit a filled channel of squared section. Within these channels, octahedral Ti-centered chains are developed along the c axis.