The title compounds were prepared by direct reaction of the corresponding elements at high temperature. Their structures were determined by single-crystal X-ray diffraction (Cs24Nb2In12As18, triclinic, P $(1) over bar $, Z = 1, a = 9.519(4), b = 9.540(5), and c = 25.16(1) Angstrom, alpha = 86.87(4), beta = 87.20(4), and gamma = 63.81(4)degrees; Cs13Nb2In6As10, triclinic, P $(1) over bar $, Z = 1, a = 9.5564(5), b = 9.6288(5), and c = 13.9071(7) Angstrom, alpha 83.7911(8), beta = 80.2973(8), and gamma = 64.9796(8)degrees). Cs(24)Nb(2)ln(12)As(18) and Cs13Nb2In6As10 contain isolated anions of [Nb(2)ln(12)As(l8)](24-) and [Nb2In6As10](13-), respectively. Each anion includes two cubane-like units made of one niobium, three indium, and four arsenic corners where a fifth arsenic atom completes the tetrahedral coordination at niobium, [(NbAs)ln(3)As(4)]. In Cs13Nb2In6As10 these two units are connected via a direct In-In bond between two indium vertexes of the cubanes. In Cs(24)Nb(2)ln(12)As(18), on the other hand, the same two units are linked by a dimer made of semicubanes of [In3As4], i.e., a cubane with one missing vertex. Magnetic measurements show that Cs(24)Nb(2)ln(12)As(18) is diamagnetic, i.e., a d(0) transition-metal Zintl phase, while Cs(13)Nb(2)ln(6)As(10) exhibits a Curie-Weiss behavior that corresponds to one unpaired electron.