In this work, the electrochemical activation of multi-walled carbon nanotube screen-printed electrode (SPEMWCNT) was proposed for the electroanalytical determination of sulfentrazone (SFZ). Determination of SFZ was carried out by square wave voltammetry (SWV) in 0.04 mol L-1 Britton-Robinson (BR) buffer solution of pH 5.0 at electrochemically activated SPE-MWCNT. The effects of various parameters on the response of the electrode such as cleaning, pH of the buffer, and SWV parameters were investigated. The SFZ oxidation peak current obtained from SWV increased linearly with its concentration at the range of 1.0-25 mu mol L-1, with the Pearson correlation coefficient r = 0.9995 and detection limits were lower than 0.8 mu mol L-1 for pure water. The developed voltammetric method for SFZ determination using disposable sensor electrodes is low cost and revealed good accuracy, repeatability and reproducibility. The relative standard deviation (RSD) values obtained for repeatability and reproducibility studies were 0.94 and 0.59% respectively, which indicate no significant variation in the electrodes after electrochemical activation. Recovery rates for measurements in soy milk and groundwater samples were 98.67% and 99.00%, respectively, indicating that the proposed electroanalytical method can be employed to analyze SFZ in these samples.