► Surface modification of Pd electrode by potentiostatic deposition of silver. ► Three-dimensional deposition of silver on the Pd substrate. ► Effect of the amount of the deposited silver on catalytic activity of Pd electrode. ► Improved activity of Ag-modified Pd electrodes for allyl alcohol oxidation. The surface modification of Pd polycrystalline electrodes with silver and the electrocatalytic oxidation of allyl alcohol on Ag-modified Pd electrodes in alkaline solution have been investigated. Ag-modified Pd electrodes with different silver loadings were prepared by means of potentiostatic deposition of silver. Scanning electron microscope images demonstrate that Ag particles and cloud-like clusters of different sizes and shapes are formed on the Pd substrate, indicating three-dimensional deposition of silver, and that a large part of the Pd substrate is not covered by silver. The results of cyclic voltammetric measurement display that allyl alcohol oxidation on the Ag-modified Pd electrodes shows a slight negative shift in peak potential and a significant variation in peak current compared to those on Pd electrode. The peak current on the Ag-modified Pd electrodes is closely related to the amount of the deposited silver, much higher peak current than that on Pd electrode can be obtained. The results of chronoamperometric measurement show enhanced anti-poisoning ability of the Ag-modified Pd electrodes. Silver modification is found to be an effective method to improve electrocatalytic activity and stability of Pd electrode for allyl alcohol oxidation.