In this work, two organotin(IV) compounds viz. triphenyltin(IV) diisopropyldithiocarbamate (1) and dimethyltin(IV) diisopropyldithio-carbamate (2) were synthesized via in situ method. Both synthesized organotin(IV) complexes were characterized by elemental, FT-IR and 1H, 12C and 119Sn NMR spectroscopies. The single-crystal structure of compound 1 was determined by X-ray single-crystal analysis. The elemental analysis data showed agreement with the suggested formulas of (C6H5)3Sn[S2CN(C3H7)2] (1) and (CH3)2Sn[S2CN(C3H7)2]2 (2). The important infrared absorbance peaks, ν(C=N) and ν(C=S), were detected in the ranges 1477-1474 cm-1 and 1038-997 cm-1 respectively. The chemical shift of carbon in the NCS2 group for compounds 1 and 2 was observed at 196.97 ppm and 198.11 ppm, respectively. The crystal structure of compound 1 showed that it is 5-coordinated and crystallized in a triclinic, P1 space group with the crystal cell parameter: a = 9.7572(1) Å, b = 11.7030(2) Å, c = 11.7602(2)Å, α = 74.419(1)°, β = 80.114(1)°, γ = 67.285(2)° and R = 0.002. The cytotoxicity (IC50) of these two compounds against K562 leukaemia cells was 0.25 μM and 4.3 μM, respectively, as assessed using MTT assay. In conclusion, the study demonstrates that both compounds showed potent cytotoxicity towards the K562 cell line tested, with compound 1 displaying a greater effect.