The conducted experimental and field studies of the process of cleaning oil-contaminated soils in the Balakhan region of the Absheron Peninsula have allowed the establishment of the combination of the most effective parameters significantly influencing the process performance. Per the research objective, the assessment of their impact and optimization of the cleaning process for oil-contaminated soils were conducted. The processing of experimental data formed the basis for the mathematical model of the process based on the equation. This equation revealed that the alkali content in the washing solution had the most significant influence on the cleaning degree, while the other parameters were less significant. Additionally, there was no multicollinearity among all factors. The established values of technological parameters that provided the highest degree of cleaning for oil-contaminated soils in the Balakhan region were as follows: using a solution containing 0.065% NaOH, 0.1% surfactant, 0.5% solvent, and mechanical action for 20 min. To verify the adequacy of the obtained mathematical model, a series of parallel experiments were conducted, and the results fell within the calculated confidence intervals of the evaluation criterion. As a result of the optimization process, the degree of cleaning of oil-contaminated soils in the Balakhan region increased by 3%, reaching 98.9%. The obtained results can be beneficial for the large-scale implementation of the process of cleaning oil-contaminated soils.