Reduced graphene oxide (RGO) decorated with tin nanoparticles (SnNPs) was electrodeposited on glassy carbon sheet (GCS), i.e. G-Sn/GCS, with a drop-casting method followed by constant potential electroreduction. Raman spectroscopic analysis on the graphitic structure of the G-Sn/GCS confirmed a good intercalation of SnNPs in the RGO matrix. Field emission scanning electron microscopic measurements illustrated a uniform distribution of the SnNPs on the RGO sheets. The G-Sn/GCS showed a better electroanalytical performance than the bare GCS and RGO/GCS in the simultaneous determination of divalent cadmium ions (Cd2+), lead ions (Pb2+) and copper ions (Cu2+) using square wave anodic stripping voltammetry. The electroanalytical measurements using the G-Sn/GCS were optimized at 1 V for 150 s in a 0.1 M acetate buffer solution (pH 5). The G-Sn/GCS demonstrated a highly linear behavior in the detection of Cd2+, Pb2+ and Cu2+ in the concentration range of 10 nM to 100 nM with detection limits of 0.63 nM, 0.60 nM and 0.52 nM (S/N=3), respectively. A mechanism for the formation of the G-Sn nanocomposite was proposed in this paper. (C) 2015 Elsevier Ltd. All rights reserved.