This work reports on the electroanalytical performance of a glassy carbon electrode (GCE) modified with antimony and bismuth (Sb/Bi‐GCE) in detecting heavy metal ions using lead and cadmium as model analytes. The electroanalytical performance of the Sb/Bi‐GCE surface was compared to the bismuth modified glassy carbon electrode (Bi‐GCE) as well as the antimony modified glassy carbon electrode (Sb‐GCE). The Sb/Bi‐GCE exhibited excellent figures of merit compared to Bi‐GCE and Sb‐GCE surfaces. For example, the limit of detection for lead was 0.01 ppb using Sb/Bi‐GCE and 0.1 and 1 ppb on Bi‐GCE and Sb‐GCE, respectively.