A series of iridium(III) dimers were synthesized and their ability to interact with diethyldithiocarbamate for CS2 sensing was evaluated. Upon the addition of CS2, diethylamine can capture CS2 to form diethyldithiocarbamate, which could chelate with the iridium(III) dimer to form a diethyldithiocarbamate iridium(III) complex, resulting in a yellow luminescence. Dimer 8 exhibited a maximum 18-fold of luminescence enhancement upon the addition of CS2. The luminescence signal of the detection system could be readily distinguished from the highly fluorescent media using time-resolved emission spectroscopy (TRES). The capability of the system to determine CS2 level in water samples was also demonstrated.