The electro-oxidation of 3,4-dihydroxyphenylalanine (L-dopa) and acetaminophen (Acet) has been investigated by the application of single-walled carbon nanotube/chitosan/ionic liquid modified glassy carbon electrode (SWCNT-CHIT-IL/GCE) using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA) methods. The modified electrode worked as an efficient electron-mediator for L-dopa and Acet. The DPV data showed that the obtained anodic peak currents were linearly dependent on the L-dopa and Acet concentrations in the range of 2-450 μM and 1-420 μM, respectively. The fabricated sensor revealed some advantages such as convenient preparation, high sensitivity, good repeatability and stability. The experimental results revealed that SWCNT-CHIT-IL/GCE could be successfully employed as an electrochemical sensor for the simultaneous determination of L-dopa and Acet in human serum and urine.