This study investigated the influence of five factors on the degree of extraction of a petroleum pollutant from a soil matrix using a Soxhlet apparatus. In order to determine the optimal combination of the five factors, that is, the number of cycles per hour, extraction time, solvent type, the amount of drying agent, and the amount of water added, a Taguchi experimental design was used: five variables (with four levels each) in an L’16 orthogonal array. Optimum extraction conditions were found to be as follows: 50.0 mL of dichloromethane, 2 h extraction time, 7 cycles, 1.0 mL of water added/5.0 g of soil, and 1.5 g of sodium sulfate/5.0 g of sample. Using the presented method, more than 90% of the diesel fuel introduced into the model matrix was extracted. This indicates that the procedure is reliable and should be applied for environmental monitoring.