The tetramethylthiuram monosulphide (TMTMS) and tetraethylthiuram disulphide (TETDS) explored as suitable ionophores to investigate the interaction of thiuram ligands with heavy metal ions. Ion selective sandwich membrane method was used to determine stability constants. It displays good logβILn (for Ag+ with TMTMS and TETDS ~6.7 and for Hg+ with TMTMS and TETDS ~6). The response time and life times are 14 s and eight weeks respectively over a wide pH range (3.5 - 9.5). Interference from other metal ions is very low and it can be used as indicator electrode in the potentiometric titration of silver and mercury ions and to determine their concentrations in agricultural soil water samples.