A carbon-paste electrode modified with 2,7-bis(ferrocenyl ethyl)fluoren-9-one (2,7-BF) and carbon nanotubes (CNTs) was used for the sensitive and selective voltammetric determination of N-acetylcysteine (NAC). The mediated oxidation of NAC at the modified electrode was investigated by cyclic voltammetry (CV). Also, the values of catalytic rate constant (k), and diffusion coefficient (D) for NAC were calculated. Differential pulse voltammetry (DPV) of NAC at the modified electrode exhibited two linear dynamic ranges with a detection limit (3) of 52.0 nmol L −1 . DPV was used for simultaneous determination of NAC and acetaminophen (AC) at the modified electrode, and quantitation of NAC and AC in some real samples by the standard addition method