A novel, simple and sensitive electrochemical procedure using a bismuth film screen-printed carbon electrode (BiF/SPCE) and differential pulse voltammetry (DPV) was developed for the determination of caffeine in non-pretreated environmental water samples. A diffusion-controlled process of the electrochemical oxidation of caffeine at the BiF/SPCE was confirmed by cyclic voltammetric studies. The linear concentration range from 1 x 10(-7) to 2 x 10(-5) mol L-1 (r = 0.9927), as well as detection and quantification limits of 2.7 x 10(-8) and 9.0 x 10(-8) mol L-1, respectively, were achieved at optimized procedure conditions and parameters. Of note, the influence of possible interfering agents appeared to be minor, which substantiates good selectivity of the procedure. The proposed procedure with the BiF/SPCE was successfully applied for the determination of caffeine in spiked river water samples with satisfactory recoveries (100.2 to 105.0%) and good agreement to the results obtained by reference high performance chromatography with photodiode array detector. Thus, the bismuth film screen printed carbon electrode is an environmentally acceptable (green) sensor for the monitoring of caffeine contamination. (C) 2017 The Electrochemical Society. All rights reserved.