Metoprolol tartrate (MET) is a selective β-adrenergic antagonist used in the treatment of cardiovascular diseases. MET overdose can affect the heart, blood pressure, breathing, and nervous system. Hence, sensitive and easy methods are required for its determination. In this work, we report a simple approach for fabrication of a bimetallic Cu/Ni modified carbon paste electrode (Cu/Ni/CPE) for electrocatalytic oxidation and determination of the metoprolol drug. At first, using the electrodeposition method, Ni was deposited on the carbon paste electrode at room temperature; then, a galvanic replacement reaction was applied for the replacement of some nickel atoms with Cu atoms. Effective parameters on electrode response to metoprolol were optimized. In optimized conditions, the bimetallic modified electrode exhibited higher electrocatalytic activity for metoprolol than a single metal modified electrode: Cu/Ni/CPE has a wider linear range and higher sensitivity to metoprolol respect to Ni/CPE. The surface of Cu/Ni/CPE was characterized by field emission scanning electron microscopy (FE-SEM) and Energy-dispersive X-ray spectroscopy (EDX). The linear dynamic range of this modified electrode for metoprolol is 1×10^-5 to 7×10^-4 M, and the limit of detection was determined to be 2.9 µM. Finally, this modified electrode was applied for the determination of metoprolol in human plasma and tablet samples, and acceptable results were obtained. For comparison, spectrophotometry was used as the reference method.