The current trend in remediating contaminated soil by acid washing is to separate the soil mass by their particles sizes prior to washing. However, there is little information about the cost-effectiveness of this practice in literature. In this research, a cadmium-contaminated agricultural field has been selected for conducting a comparative study on cadmium removal by applying the acid washing method to soil samples with and without prior particle separation. The study provides valuable information for the advancement of this method to remediate contaminated soil. The results indicate that sand particles constitute about 70% of the total soil mass but only 24% of the total cadmium. After acid washing once, less than 2% of cadmium remains; multiple washing of the sand portion is thus not cost-effective. Furthermore, after particle separation, the soil mass that needs to be washed is greatly reduced to 35%; the total cost is reduced by about one third due to the savings in the acid solution utilization and the treatment of used acid solution.