A modified carbon nanotube paste electrode was used for the sensitive and selective voltammetric determination of norepinephrine (NE). The mediated oxidation of NE at the modified electrode was investigated by cyclic voltammetry (CV). Under the optimum conditions, the calibration curve for NE was obtained in the range of 0.03-500.0 μΜ with a detection limit (3σ) of 22.0 nM using differential pulse voltammetry (DPV). DPV was used for simultaneous determination of NE and acetaminophen (AC) at the modified electrode, and quantitation of NE and AC in some real samples by the standard addition method.