Storage location assignment is an important decision problem in warehouse operations management. Because the main purpose of the storage location assignment system is to create various parameters to facilitate the diagnosis and positioning of the products in the warehouse. In addition, time spent on storage activities is an important factor in the demand cycle. However, uncertainty in product demands causes various problems in assigning products to storage locations. Therefore, it is necessary to research viable and sustainable tools in cases of uncertainty. One of these tools is fuzzy decision making methods, which are frequently used in the literature and give effective results. In this study, it is proposed to rank the products with the Fuzzy PROMETHEE (F-PROMETHEE) method under qualitative criteria for warehouse systems where the demand is uncertain and assign them to the most suitable storage locations according to this rank. The effectiveness of the proposed approach has been tested with a small sample problem. Criteria addressed for this problem are demand, profitability and sensitivity. Solution results have shown that the proposed approach is effective.