A new graphene/zinc oxide nanorods modified glassy carbon electrode (GR/ZnORs/GCE) based electrochemical sensor has been developed for the sensitive determination tizanidine (TZ) in solubilized system. The fabricated sensor was characterized by various electrochemical methods. Different kinetic parameters affecting the monitored electrocatalytic response were investigated and optimized for tizanidine determination at fabricated GR/ZnORs/GCE sensor and successfully compared with the results obtained at GR/SiO2/GCE, GR/GCE and at bare GCE. Under optimized conditions the square wave current is linear over the concentration range 0.80 ng mL(-1) to 10.0 mu g mL(-1) with detection limit and quantification limit of 0.10 ng mL(-1) and 3.45 ng mL(-1) respectively. The applicability of proposed method is further extended to in vitro determination of the drug in pharmaceutical formulation with an acceptable recovery from 97.89% to 101.09%. (C) 2016 Elsevier B.V. All rights reserved.