The effect of heavy metals on the degradation of carbofuran by immobilized bacterial cells was checked by culturing in the MSM medium at 37^oC in the presence of 0-1 mg/L of heavy metals. Bioremediation systems represent a biologically sustainable means to degrading organic pollutants such as carbofuran insecticide, with little energy demand and operational expenses in addition to high efficiency and substrate specificity. Nonetheless, heavy metals present in the agricultural lands may thwart the process efficiency by poisoning carbofuran-degrading microbial isolates. Therefore, we experimentally tested the tolerance of carbofuran-degrading immobilizedbacterial isolated from vegetable plantation area for mercury (Hg) and copper (Cu). The results indicated that the tested metals inhibited carbofuran biodegradation to different extents, depending on concentration. At pH 7.0 and 37°C, complete inhibition of carbofuran biodegradation by Hg occurred at 0.4, 0.5, 0.6 and 0.7 mg/L. Lower concentrations of these metals decreased the rate of carbofuran− biodegradation, with relatively long lag times. Interestingly, the immobilize isolate tolerated higher concentrations, although both the rate and extent of carbofuran− biodegradation were affected.