This article reports the electrochemical determination of caffeine in the presence of paracetamol (PA) using a self-assembled monolayer (SAM) of non-peripheral amine substituted copper(II) phthalocyanine (4 alpha-Cu(II)TAPc) on glassy carbon electrode (GCE). The 4 alpha-Cu(II)TAPc SAM modified GCE shows two pairs of redox waves at 0.16V and 0.23 V. corresponding to Cu-II/Cu-I and Pc-1/Pc-2, respectively. The 4 alpha-Cu(II)TAPc SAM modified GCE exhibits an excellent electrocatalytic activity toward caffeine. Further, it was successively used for the selective and simultaneous determination of caffeine in the presence of PA. The differential pulse voltammetric current responses of caffeine were increased linearly while increasing the concentration of caffeine in the range of 0.005-1.4 mM and a detection limit was found to be 3.04 x 10(8) M (S/N = 3). Further, the modified electrode successfully recovers caffeine in blood serum samples. The present method was also applied for the determination of caffeine in cola drinks and simultaneous determination of caffeine and PA in pharmaceutical formulations. The results obtained from the present method were validated with the HPLC method. (C) 2012 Elsevier Ltd. All rights reserved.