Mixed iodotris(dithiocarbamato)tellurium(iv) complexes TeL3I (where L- = R1R2NCS2-) have been synthesized with the use of the oxidative replacement reaction via the interaction of TeL4 with iodine. Thus, complexes with R1 = R2 = methyl, ethyl, isopropyl, propyl, and with R1R2N = piperidinyl* have been prepared. A single-crystal structure analysis of one of these, iodotris(piperidine dithiocarbamato)tellurium(iv), is also reported. In the structure the tellurium atom exists in a distorted pentagonal-bipyramidal environment with the iodine atom and one sulfur atom occupying axial positions. The axial Te-S bond of 2·555(2) Å is shorter than the remaining Te-S bonds in the complex [range 2·671(2)-2·722(2) Å]. Crystals are monoclinic, space group P21/n with unit cell parameters a 9·891(2), b 18·889(2), c 14·762(2) Å β 98·85(2)° and Z 4. The structure was refined to final R 0·035 and Rw 0·052 for 3283 reflections with I ≥ 1·25σ(I). © 1989, CSIRO. All rights reserved.