Sol-gel-immobilized-urease conductometric biosensor on a thick film interdigitated electrode was developed. The biosensor can be used for heavy metal ions determination in liquid samples. The biosensor exhibited good response to changes in urea concentration within the range of 1mM to 15 mM. After standardizing the sensor for Urea, the biosensor has been used to determine the heavy metal ions of different concentrations. The concentration range of Urea that can be detected by using this sensor is 1mM to 15mM.The heavy metals range is from 0.1mM to 10mM. Among the three metals used, the amount of inhibition is found to be more in Cadmium, then Copper and then Lead. The sensitivity is 1 mM in spectrophotometric technique and 5 mM in electrical method. The described sensor is tested for synthetic effluents in laboratory conditions. By further refinement, it can be used to test real industrial samples. © 2006 Taylor and Francis Group, LLC.