Gold nanoparticles-modified glassy carbon electrode was utilized in the present study to determine trace amount of Cr(VI). The steps employed in the present study were fabrication of gold nanoparticles colloids, modification of glassy carbon electrode using the gold nanoparticle colloids, and voltammetric determination of Cr(VI) using the modified electrode. The results of the present study indicate that 290μL of 0.1M NaBH₄ was required to form gold nanoparticles colloids. Self assembly process was found to give better gold nanoparticles binding onto glassy carbon electrode compared to adsorption process as indicated by more gold nanoparticles attached onto the glassy carbon electrode. Modification of the glassy carbon electrode using gold nanoparticles increase sensitivity as indicated by good limit of detection (2.38 ng/L) with an acceptable linearity range within 0.050 – 0.250μg/L. The correlation coefficient and precision of the method were 0.9948 and 99.14%, respectively.