A new cluster of formula {[Mo3(μ3‐S)(μ‐S)(μ‐S2)2(dtp)3(μ‐OAc)][Mo3NiS4(dtp)3(μ‐OAc)(CH3CN)]} (1; dtp = diethyl dithiophosphate; OAc = acetate) comprising the novel Cs‐symmetrized Mo3(μ3‐S)(μ‐S)(μ‐S2)2 structural type covalently attached to a cubane‐type Mo3NiS4 core has been isolated and fully characterized. The reaction of a 2 M HCl solution of [Mo3S4(H2O)9]4+ with an excess of potassium diethyl dithiophosphate and acetic acid in the presence of the [Mo3(NiCl)S4(H2O)9]3+ cluster afforded a mixture of products encompassing different Mo3Sx (x = 4–7) cluster cores from which the Mo3(μ3‐S)(μ‐S)(μ‐S2)2 structural type has been isolated in analytically pure form as a Mo3NiS4 adduct. The robustness of the aggregate 1 was also retained in solution as judged by ESI‐MS and 31P NMR techniques. Single‐crystal X‐ray analysis revealed in detail the complementary association of the newly formed Mo3(μ3‐S)(μ‐S)(μ‐S2)2 entity and the Mo3NiS4 cluster in which μ‐S sulfide ligands and μ‐S2 disulfide ligands act as nucleophilic and electrophilic functional groups, respectively, towards the Mo3NiS4 cube through directional Ni–S covalent bonds and short S···S contacts (below 3.3 Å).