A chemically modified electrode is constructed based on multi-walled carbon nanotube modified glassy carbon electrode (MWCNTs/GCE) as a sensor for simultaneous determination of acetaminophen (ACT) and indomethacin (INDO) in phosphate buffer (pH 7) solution. The measurements were carried out using differential pulse voltammetry (DPV), cyclic voltammetry (CV) and chronoamperometry (CA) methods. DPV measurements showed that the linear relationship between oxidation peak current and concentration of ACT and INDO were in the range of 3 μM to 400 μM, and 10 μM to 330 μM, respectively. Under optimal conditions the modified electrode exhibited high sensitivity and stability for both ACT and INDO determination, making it a suitable sensor for the simultaneous submicromolar detection of ACT and INDO in solutions. The analytical performance of this sensor has been evaluated for detection of ACT and INDO in human serum, human urine and a pharmaceutical preparation with satisfactory results