Synthetic and structural aspects of perchlorato complexes of tellurium(IV) with different dithiocarbamates (dtc) [(R1R2NCS2) where R1 = R2 = methyl, ethyl, n-propyl, i-propyl; R1R2 = (CH2)5(piperidine), C2H4OC2H4 (morpholine)] are reported. The crystal structure of TeL3ClO4 (where L = diethyl dtc) has been determined. The crystals of the complex are monoclinic, space group P21/n, a = 11.379(3), b = 17.745(7), c = 14.016(8) Å, γ = 103.30(2)°, V = 2754.2 Å3, F(000) = 1352, DX = 1.61 mg M-3. The final R and Rw values are 0.047 and 0.058, respectively for 5224 unique reflections. Tellurium displays a distorted dodecahedral stereochemistry formed by two interposing trapezoids, one resulting from the four sulphurs of two L groups and the other from the two sulphurs of the third L and the two oxygens of the perchlorate ion. The average TeS distance 2.648(2) Å is close to that reported in other tris(dithiocarbamato)tellurium(IV) complexes. The perchlorate is weakly coordinated to tellurium(IV), with the average TeO distance being 2.994(8) Å. The unusual coordination of perchlorate (as a bidentate ligand) to tellurium(IV) dithiocarbamate is reported for the first time. © 1989.