The present work investigates the electrocatalytic properties of the palladium nanoparticles based polymer nanocomposite towards sensing of Melatonin (MEL). The modification protocol involved a single step fabrication and was achieved using cyclic voltammetry. The sensing surface was characterized using voltammetry, FE-SEM, EDX and EIS. Quantitative estimation of MEL has also been carried out using square wave voltammetry in the linear concentration range of 5-100 mu M and sensitivity and limit of detection of 0.1235 mu A/mu M and 0.09 mu M respectively have been achieved. The surface modified sensor exhibited almost 3 fold improvement in the sensing properties in comparison to the unmodified surface. The proposed method was also successfully extended for the determination of MEL in commercially available pharmaceutical formulations and human urine samples. (C) 2016 Elsevier Ltd. All rights reserved.