The structural analysis of Cd 3[Mn(CN) 5NO] 2·15H 2O using single-crystal diffractometry and full-matrix least-squares refinement has yielded residuals of 0.027 ( R) and 0.034 ( R w) based on 2659 observed reflections. The nitrosyl complex crystallizes in the centrosymmetric triclinic space group P 1 with cell parameters a=7.8349(9), b=9.6412(7), c=12.7208(7) Å, α=99.022(5), β=106.591(6), γ=102.152(7)°, V=875.8(1) Å 3 and Z=1. The observed density is 1.99(1) g cm −3 ( D c=1.97(1) g cm −3). A thermogravimetric study reveals 14–15 water molecules per formula unit. Both Cd and Mn atoms have slightly distorted octahedral geometries and are linked by cyanide bridging. Within any given chain of CdMnCdmnCd, the end cationic Cd atoms are fac-coordinated by three cyanide groups and three water molecules. Whereas, the central Cd atom is ligated to four cyanide groups and two trans-oriented water molecules. The Mn atoms are bonded to five cyanide bridging groups and one nitrosyl group. Notable bond lenghts are: Cd N(mean) =2.28(4), Cd(mean)O=2.37(4), MnC(mean) 1.99(2), MnNO=1.645(4), NO=1.174(7) and C=N(mean)=1.144(7) Å. Infrared spectroscopic data are presented.